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Commercial potential of Giant Reed for pulp, paper and biofuel production Book · December 2010

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Commercial Potential of Giant Reed for Pulp, Paper and Biofuel Production RIRDC Publication No. 10/215

RIRDC

Innovation for rural Australia

Commercial Potential of Giant Reed for Pulp, Paper and Biofuel Production by Dr Chris Williams and Dr Tapas Biswas With the Support of FibreCell Australia Pty Ltd

December 2010 RIRDC Publication No. 10/215 RIRDC Project No. PRJ-000070

© 2010 Rural Industries Research and Development Corporation. All rights reserved. ISBN 978-1-74254-180-8 ISSN 1440-6845 Commercial Potential of Giant Reed for Pulp, Paper and Biofuel Production Publication No. 10/215 Project No. PRJ-000070 The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable regions. You must not rely on any information contained in this publication without taking specialist advice relevant to your particular circumstances. While reasonable care has been taken in preparing this publication to ensure that information is true and correct, the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication. The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the part of the Commonwealth of Australia, RIRDC, the authors or contributors. The Commonwealth of Australia does not necessarily endorse the views in this publication. This publication is copyright. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. However, wide dissemination is encouraged. Requests and inquiries concerning reproduction and rights should be addressed to the RIRDC Publications Manager on phone 02 6271 4165. Researcher Contact Details Dr Chris M. J. Williams South Australian Research and Development Institute Sustainable Systems, Water Resources and Irrigated Crops GPO Box 397 Adelaide SA 5001.

Associate Professor Jim Cox, South Australian Research and Development Institute Sustainable Systems Water Resources and Irrigated Crops GPO Box 397 Adelaide SA 5001.

Phone: 08 8303 9567 Fax: 08 8303 9473 Email: retired 2009

Phone: 08 8303 9334 Fax: 08 8303 9473 Email: [email protected]

In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. RIRDC Contact Details Rural Industries Research and Development Corporation Level 2, 15 National Circuit BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: Fax: Email: Web:

02 6271 4100 02 6271 4199 [email protected]. http://www.rirdc.gov.au

Electronically published by RIRDC in December 2010 Print-on-demand by Union Offset Printing, Canberra at www.rirdc.gov.au or phone 1300 634 313

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Foreword In Australia and many other countries, escalating demands for high quality water resources, arable land, food and fossil fuels is rapidly growing. With an emerging “feed versus fuel debate” there is a pressing need to find options for the use of marginal lands (unsuited for food crops) and wastewaters or saline ground waters to produce second generation biofuel or biopaper crops. Arundo donax (A. donax) was selected as a potential crop for use in this area. Research shows it can produce 45.2 tonnes/hectare/year grown on marginal land using saline winery wastewater for irrigation. In addition A. donax can produce more lignocellulosic biomass using less land than other alternative biomass crops currently grown on marginal lands. Laboratory studies demonstrate that A. donax can produce up to 240 L of bioethanol per oven dry tonne of biomass, with potential of up to 350 L. Weed risk management guidelines have been developed for A. donax in Australia. This project was funded from the industry revenue which is matched by the funds provided by the Australian Government. This report is an addition to RIRDC’s diverse range of over 2,000 research publications and it forms part of our New Rural Industries R&D program, which aims to provide the knowledge for diversification in Australia’s rural industries. Most of RIRDC’s publications are available for viewing, free downloading or purchasing online at www.rirdc.gov.au. Purchases can also be made by phoning 1300 634 313.

Craig Burns Managing Director Rural Industries Research and Development Corporation

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Acknowledgments The project team acknowledges the funding provided by the Rural Industries Research and Development Corporation of Australia and FibreCell Australia Pty Ltd and South Australian Research and Development Institute for financial support. . The authors thank Mr Lyndon Palmer and Mrs Teresa Fowles of Waite Analytical Services of the Plant Science Department, University of Adelaide, Waite Campus for chemical analyses, and the staff of the Analytical Crop Management Laboratory at Loxton for total nitrogen and organic carbon analyses. Thanks go to Mr D. Maschmedt, formerly of Primary Industries and Resources, South Australia for the soil classifications. We thank Dr Lin Lin Low of Constellation Wines, Berri Estates, South Australia for storage and flood irrigation of winery wastewaters to the A. donax crops at Barmera; John Matheson and Paul Harris (University of Adelaide) for provision of wastewaters and application of the drip irrigations on the Roseworthy A. donax crops. Also included in our thanks are Mr Stephen Heading and the dedicated team of casuals who assisted in the experimental work. Special thanks to Louise Chvyl for her indispensable, most capable assistance with tabulation of data, and compilation of this report. We also thank Ms Adrienne Twisk for most capable assistance with formatting and final revisions of this report.

Please note: Dr Williams retired in December, 2009, and Dr Biswas has moved to a new position interstate. Please direct all enquiries, in the first instance, to Associate Professor Jim Cox, Principal Scientist, Water Resources and Irrigated Crops, SARDI, GPO Box 397, Adelaide, South Australia 5001. His email is [email protected].

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Contents Foreword

......................................................................................................................................... iii

Acknowledgments ................................................................................................................................ iv Executive Summary ............................................................................................................................. xi Introduction .......................................................................................................................................... 1 Objectives

.......................................................................................................................................... 2

Methodology .......................................................................................................................................... 3 Chapter 1: Dry matter yield, carbon accumulation and biochar from Arundo donax grown in South Australia ............................................................................................... 4 Chapter 2: Salt tolerance and nutrient dynamics of Arundo donax ............................................... 20 Chapter 3: Weed risk management guidelines for Arundo donax plantations in Australia ........ 42 Chapter 4: Evaluation of Arundo donax for pulp/paper ................................................................. 70 Chapter 5: Pretreatment and fermentation studies for second generation ethanol production from Arundo donax ................................................................................... 72 Chapter 6: Arundo donax in the upper South East of South Australia ......................................... 82 Implications ........................................................................................................................................ 89 Recommendations ............................................................................................................................... 90 Appendices ........................................................................................................................................ 91 References

...................................................................................................................................... 143

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Tables Table 1.1:

Treatment details for experiments on arable soil at Roseworthy ....................................................... 6

Table 1.2:

Dry matter (DM) biomass yields (t/ha) at Roseworthy at each clearfell for the A. donax old stand (first clear felled 7/06/2005 after 30 years) .............................................................................. 9

Table 1.3:

Organic carbon (t/ha) sequestered at Roseworthy at each clearfell, from the A. donax old stand (first clearfelled 7/06/2005). .............................................................................................................. 9

Table 1.4:

Stem height, diameter, number, dry weight and percent dry matter for 5 June 2006 clearfell harvest at Roseworthy...................................................................................................................... 11

Table 1.5:

Dry matter (DM) biomass yields at Barmera CF at each clearfell* .................................................. 15

Table 1.6:

Organic carbon sequestered at Barmera CF at each clearfell* ......................................................... 15

Table 1.7:

Maximum yield, net energy, fuels/year (mean value from the second to the twelfth year of growth, Italy). .................................................................................................................................. 18

Table 2.1:

Suction tube soil water ECswe (dS/m), at Barmera, from January 2008 to March 2009a................ 25

Table 2.2:

Suction tube soil water extract nitrate-N (mg/L), at Barmera, from January 2008 to March 2009a. ................................................................................................................................... 26

Table 2.3:

Average carbon and macro-nutrient concentrations (% on a dry matter basis) of A. donax at Barmera for 3 annual clearfell harvests. .......................................................................................... 30

Table 2.4:

Average carbon and macro-nutrient uptake by A. donax at Barmera at 3 annual clearfell harvests. ........................................................................................................................................... 31

Table 2.5:

Nutrient concentrations for 23 March 2006 harvest for the established planting at Roseworthy ... 33

Table 2.6:

Nutrient uptake for 23 March 2006 harvest for the established planting at Roseworthy ................. 33

Table 2.7:

Average macro-nutrient concentrations of A. donax at Roseworthy final harvest 2009 .................. 34

Table 2.8:

Average macro-nutrient removals for Roseworthy final harvest 2009 (25/06/2009) ....................... 34

Table 2.9:

Average macro-nutrient concentrations in the rhizomes, string and hair roots for 2 annual harvests of A. donax at Barmera........................................................................................... 35

Table 2.10:

Average meso-nutrient concentrations of the rhizomes, string and hair roots of A. donax for 2 annual harvests at Barmera ........................................................................................................... 36

Table 2.11:

Average micro-nutrient concentrations in the rhizomes, string and hair roots of A. donax for 2 annual harvests at Barmera. .......................................................................................................... 37

Table 2.12:

Comparison of soil organic carbon and nutrients at 29 June 2005 and 28 February 2006 at Roseworthy for the established planting at different soil depths...................................................... 38

Table 2.13:

Soil organic C and macro-nutrients at the final sampling (June 2009) of the A. donax clearfell treatments at the Roseworthy sites. .................................................................................... 38

Table 2.14:

Comparison of soil average organic C and macro-nutrients at the start (May 2006), middle (May 2007) and end (June 2009) under A. donax clearfell treatments at the Barmera site ............. 39

Table 2.15:

Soil average organic C and macro-nutrients at the start (May 2006), middle (May 2007) and end for the control area of the Barmera trial .................................................................................... 40

Table 5.1(a): Inhibitory compounds derived from acid/enzyme hydrolysate (10% w/v) of A. donax. .................. 79 Table 5.1(b): Inhibitory compounds derived from alkali/enzyme hydrolysate (10% w/v) of A. donax. ................ 79 Table 5.2:

Summary of pretreatment and fermentation results for 10% (w/v) A. donax. .................................. 80

Table 6.1:

Preliminary cost assumptions for A. donax plantations ($/ha) ......................................................... 84

Table 6.2:

Preliminary industrial A. donax growing system costs/ha: summary ($) ......................................... 85

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Table 6.3:

Preliminary factory gate “oven dry” tops $/t to achieve 15% IRR and mature A. donax plantation yields (t/ha/year of “oven dry” tops) ............................................................................... 85

Table 6.4:

IRR results for conversion factories using A. donax feedstock sited in the South East of South Australia (central price estimates shown first in each series). ............................................... 87

Appendix Tables Table 1.A.1: Soil profile descriptions for A. donax sites at Barmera, South Australia. ....................................91 Table 1.A.2: Roseworthy Monthly Weather Data ........................................................................................92 Table 1.A.3: Loxton Research Centre Monthly Weather Data ......................................................................93 Table 1.B.1: Summary of batch pyrolysis trial results. ......................................................................................... 99 Table 1.B.2: Mass and energy balance. .............................................................................................................. 104 Table 1.B.3: Proximate and ultimate analysis results from ITA for A. donax feedstock .................................... 105 Table 1.B.4: Proximate and ultimate analysis results from ITA for A. donax biochar ....................................... 106 Table 2.A.1: Irrigation water composition (salinity (EC) and nutrients) in holding lagoon, Barmera, prior to application to Adx ab from June 2006 to July 2007. .................................................................. 107 Table 2.A.2: Irrigation water composition (salinity and nutrients) in holding lagoon, Barmera, at 7 sampling dates from September 2006 to May 2007 a. ................................................................... 108 Table 2.A.3: Irrigation water composition (salinity (EC) and nutrients) in the holding lagoon, Barmera, prior to application to Adx ab. ........................................................................................................ 109 Table 2.A.4: Irrigation water composition (salinity and nutrients) in holding lagoon, Barmera, at 9 sampling dates from January 2008 to April 2009 a. ....................................................................... 110 Table 2.A.5: Irrigation water composition (nutrients and metals in mg/L) applied in 2006 at Roseworthy. ...... 111 Table 2.A.6: Average meso-nutrient concentrations of A. donax organs at Barmera for 3 annual clearfell harvests. ......................................................................................................................................... 112 Table 2.A.7: Average meso-nutrient uptake of Adx organs for 3 annual clearfell harvests at Barmera ............. 113 Table 2.A.8: Average micro-nutrient concentrations for 3 annual clearfell harvests at Barmera ....................... 114 Table 2.A.9: Average micro-nutrient removals concentrations for 3 annual clearfell harvests at Barmera. ..... 115 Table 2.A.10: Average meso-nutrient concentrations at Roseworthy for final harvest 2009 ................................ 116 Table 2.A.11: Average meso-nutrient removals at Roseworthy for final harvest 2009 ........................................ 116 Table 2.A.12: Average micro-nutrient concentrations at final Roseworthy harvest 2009. ................................... 117 Table 2.A.13: Average micro-nutrient removals at Roseworthy for final harvest 2009 (25/06/2009).................. 117 Table 4.A.1: Pulping of A. donax ....................................................................................................................... 119 Table 4.A.2: DEpD bleaching of unbleached pulp ............................................................................................. 120 Table 4.A.3: Physical Strength Properties .......................................................................................................... 121 Table 4.B.1: Summary of types of paper ............................................................................................................ 125 Table 4.B.2: Summary of magnesium bisulphate pulping results. ...................................................................... 126 Table 4.B.3: Summary of the woodmeal and pulp analysis ................................................................................ 130 Table 4.B.4: Summary of the wood/non-wood properties .................................................................................. 133

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Figures Figure 1.1:

Potential pathways to convert cellulosic biomass to biofuels. .................................................. 4

Figure 1.2:

A. donax, old stand, 361 days after first clear fell, left: Dryland and right: Irrigated treatments at Roseworthy............................................................................................................ 9

Figure 1.3 a, b:

Dry matter (DM) and organic carbon (C) yields of A. donax top growth, at Roseworthy old stand, irrigated clearfell (CF) treatment, 2005 to 2009....................................................... 10

Figure 1.4 a, b:

Dry matter and organic carbon yields of A. donax rhizomes, at Roseworthy old stand, irrigated CF sites, 2005-2009 ................................................................................................... 10

Figure 1.5 a, b:

Dry matter and organic carbon yields of A. donax tops, at Roseworthy old stand, dryland CF sites, 2005-2009. .................................................................................................... 11

Figure 1.6 a, b:

Dry matter and organic carbon yields A. donax rhizomes, at Roseworthy old stand, dryland CF sites, 2005-2009. .................................................................................................... 11

Figure 1.7 a, b:

Dry matter and organic carbon yields of A. donax tops, at Roseworthy, new planting, CF sites, 2006-2009. ................................................................................................................. 12

Figure 1.8 a, b:

Dry matter and organic carbon yields of A. donax rhizomes, at Roseworthy new planting, CF sites, 2006-2009. ................................................................................................................. 12

Figure 1.9 a, b:

Dry matter and carbon yields of A. donax tops, at Roseworthy, new planting, uncut sites, 2006-2009........................................................................................................................ 13

Figure 1.10 a, b: Dry matter and carbon yields of A. donax rhizomes, at Roseworthy new planting, uncut sites, 2006-2009........................................................................................................................ 13 Figure 1.11:

Left: Loveday rootstock of A. donax in marginal soil at Barmera, 5 months after planting, October, 2006; Right: same A. donax at first clearfell, June 2007 (yield 45.2 t/ha dry tops). .. 15

Figure 1.12 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax tops at Barmera for the annual clearfell treatments for the Loveday (▲) and Henley Beach rootstocks (•) over 3 years to 2009. ........................................................................................................................ 16 Figure 1.13 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax rhizomes at Barmera for the annual clearfell treatments for the Loveday (▲) and Henley Beach rootstocks (•) over 3 years to 2009. ........................................................................................................................... 16 Figure 1.14 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax tops at Barmera for the annual uncut treatments for the Loveday (▲) and Henley Beach rootstocks(•) over 3 years to 2009. ........................................................................................................................... 17 Figure 1.15 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax rhizomes at Barmera for the annual uncut treatments for the Loveday (▲) and Henley Beach rootstocks (•) over 3 years to 2009. ........................................................................................................................ 17 Figure 2.1:

ECswe and other variables change with time for first year growth of A. donax at Barmera, SA for (a) Loveday, and (b) Henley Beach rootstocks. Soil solution ECswe results are from suction tubes installed at 30, 60 and 90 cm soil depths................................... 23

Figure 2.2:

Changes in salinity of the influent irrigation, ECw and soil water extracts, ECswe in dS/m, and chloride and nitrate-N concentrations (mg/L) with time for the first year of growth of A. donax at Barmera, SA for Loveday and Henley Beach rootstocks....................................... 24

Figure 2.3:

Relative yield (RY) of dry tops of A. donax in response to the salinity of the saturatedsoil extract (ECe) ...................................................................................................................... 27

Figure 2.4:

Relative yield (RY) of dry tops of A. donax in response to the saturated- soil extract (ECe). ..................................................................................................................................... 27

Figure 2.5:

Schematic representation of possible layout, flows and concentrations of salt in SBC biosystem (modified after Blackwell et al. 2000, from Biswas and Williams 2009). ............... 28

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Figure 3.1:

Predicted distribution of A. donax in Australia (based on temperature only and not refined to areas with riparian ecosystems only) ........................................................................ 48

Figure 3.2:

Scoring for Comparative Weed Risk in the riparian and terrestrial land uses. .......................... 51

Figure 3.3:

Australian herbaria records for A. donax (Australia’s Virtual Herbarium) ............................... 53

Figure 3.4:

Scoring for Feasibility of Containment in the riparian and terrestrial land uses. ....................... 56

Figure 3.5:

Weed risk management action matrix and locations of the two land uses assessed for A. donax.................................................................................................................................... 57

Figure 3.6:

Example of data generated from AFLP analysis. ................................................................... 59

Figure 3.7:

Identical individuals grouped together: the group they are in and number of individuals in that group.............................................................................................................................. 61

Figure 3.8:

Dendrogram redone with only one representative from each group of identical individuals. ... 62

Figure 3.9:

Map of SA sample locations. The 4 individuals from the second genotype (blue) are indicated with blue triangles. .................................................................................................... 63

Figure 3.10:

Map of all samples. Individuals from the second genotype (blue) are indicated with blue triangles. ................................................................................................................................... 64

Figure 5.1:

Sugar extraction using 2% H2SO4 at 121oC, 30 min followed by 2% cellulase and 4% glucosidase (Novozyme) treatment at 60o C, pH 5.0 and 180 rpm for 22 h. ............................. 75

Figure 5.2:

Sugar extraction from A. donax using 2% H2SO4 at 134oC, 60 min followed by 2% cellulase and 4% β-glucosidase (Novozyme) treatment at 60o C, pH 5.0 and 180 rpm for 22 h. ............ 75

Figure 5.3:

Sugar extraction of A. donax using 2% H2SO4 at 134o C, 60 min followed by 2 % cellulase and 4 % β-glucosidase (Novozyme) treatment at 50o C, pH 5.0 and 180 rpm for 22 h. .......... 76

Figure 5.4:

Sugar extraction using 2% H2SO4 at 134o C, 30min followed by 0.2% cellulase and 0.4% β-glucosidase (Novozyme) treatment at 50o C, pH 5.0 and 180 rpm for 22 h. ......................... 76

Figure 5 5:

Sugar extraction of 10 % (w/v) A. donax using 2% NaOH at 134o C, 60 min followed by 2 % cellulase, 2% xylanase and 4 % β-glucosidase (Novozyme) treatment at 50o C, pH 5.0 and 180 rpm for 22 h. ......................................................................................................... 77

Figure 5.6:

Fermentation profile of ZM4 (pZB5) using A. donax acid/enzyme hydrolysate derived from 10% (w/v) substrate loading using 2% H2SO4 at 134o C for 60 min followed enzyme hydrolysis at 50o C for 22 h using 2% cellulase and 4% β-glucosidase. ................................... 78

Figure 5.7:

Fermentation profile of ZM4 (pZB5) using A. donax alkali/enzyme hydrolysate derived from 10% (w/v) substrate loading using 2% NaOH at 134o C for 60 min followed enzyme hydrolysis at 50o C, pH 5.0 for 22 h using 2% xylanase, 2% cellulase and 4% β-glucosidase. 78

Figure 5.8:

Schematic diagram of 2nd generation ethanol production process using acid/enzyme hydrolysis used in this study. .................................................................................................... 81

Figure 5.9:

Schematic diagram of 2nd generation ethanol production process using alkali/enzyme hydrolysis used in this study. .................................................................................................... 81

Figure 1.B.1:

Batch pyrolysis test rig. .......................................................................................................... 97

Figure 1.B.2:

Recorded process data from batch pyrolysis run. ................................................................... 98

Figure 1.B.3:

Proximate analysis results. ................................................................................................... 100

Figure 1.B.4:

Gross calorific value results. ................................................................................................ 101

Figure 1.B.5:

Ultimate analysis results. ...................................................................................................... 102

Figure 1.B.6:

Feedstock ash constituent results.......................................................................................... 103

Figure 4.B.1:

Relationship between total pulp yield and kappa number (100% P. radiata) ...................... 127

Figure 4.B.2:

Comparison of pulp strength properties (100% P. radiata used as control). ........................ 128

Figure 4.B.3:

Samples of subdivided P. radiata (right) and Adx (left) ...................................................... 129

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Figure 4.B.4:

Sample of Adx as received (left) and after cutting with a band saw (right).......................... 132

Figure 4.B.5:

Preparation of bisulphite pulping liquor (left) and analysis of the prepared liquor (right) ... 134

Figure 4.B.6:

Picture of digester (left) and liquor extraction point (right) ................................................. 134

Figure 4.B.7:

Collection of photographs from process steps and testing equipment .................................. 141

Figure 4.B.8:

Digital photos of selected handsheets................................................................................... 142

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Executive Summary What the report is about In Australia and most countries, increasing demands for high quality water resources, arable land, food and fossil fuels are greater than the sustainable, economic supply. This report presents research on the perennial, rhizomatous grass, giant reed (Arundo donax) to assess its use: 1. On marginal lands and wastewaters or saline ground waters, to produce lignocellulosic feedstocks (together with other biomass crops) 2. For new second generation biofuels and/or pulp/paper industries for Australia. Who is the report targeted at? This report is targeted at all sectors of the Australian and overseas biomass, second generation biofuels and the pulp/paper industries. The report is also intended to inform landcare agencies, policy makers, rural industries, local, state and federal governments, research funding bodies and researchers, investment bodies, communities, environment groups, media and the general public. Background Australia has large reserves of saline ground water (over 5,000 mg/L of total soluble salts) with 3,434 GL/year of sustainable groundwater unsuitable for drinking or irrigation of traditional crops. In addition, urban and peri urban sewage wastewater produced annually is 1,824 GL, of which only 156 GL is reused. Saline soils in Australia and South Australia (SA) are estimated to cover 2.6 and 1.4 million ha, respectively. In many situations large areas of saline, marginal soils exist adjacent to the saline water resources. Research was needed to use such wastewaters to grow salt tolerant, non-food biofuel crops, such as A. donax, on nearby saline, marginal lands, develop sustainable production systems and define biomass yields, carbon accumulation and processing qualities of the biomass for biofuels or pulp/paper. A concern, however, was whether weed risk management guidelines can be developed for A. donax plantations in Australia. Also, baseline data for industry are required on the potential yield of biofuels (eg. ethanol) per dry tonne of A. donax biomass and an evaluation of A. donax for pulp/paper or biochar products and the potential economic returns. Aims/objectives •

Produce baseline data to describe the biomass growth curves, carbon accumulation and nutrient uptake by the perennial grass, A. donax (giant reed) grown on saline, marginal land and arable land.

•

Assess the yield and quality of A. donax biomass feedstocks and their conversion efficiencies to biofuels or pulp/paper.

•

Conduct, for the Australian context, a formal weed risk assessment of A. donax and compile weed risk management guidelines.

•

Estimate indicative factory gate prices for A. donax, on different classes of land and internal rates of return for enterprises producing bioenergy and other products or pulp/paper.

Results/key findings We report for the first time in Australia, growth curves for giant reed (A. donax) for dry matter biomass yields and carbon accumulation over 3 years when grown on a marginal and an arable soil.

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A. donax produced more cellulosic biomass and sequestered more carbon per annum, using less land and pesticides than any other alternative crop reported in the literature, for warm temperate to sub tropical environments and for marginal lands under similar water input regimes (either irrigated with wastewaters or grown dryland with over 450 mm of annual precipitation). A.donax was grown with no pesticides and minimal energy inputs in South Australia (SA). A. donax produced a high biomass yield of 45.2 t/ha of dry tops in the first year, when grown on saline, marginal land at Barmera in SA with winery wastewater. On arable soil in South Australia at Roseworthy Campus (near Gawler), A. donax produced 45.4, 58.4, 55.6 and 59.3 t/ha/year of dry tops each clearfell year, when irrigated with reclaimed sewage. The non-irrigated A. donax treatment at Roseworthy produced 12.6 and 12.9 t/ha of dry tops with 5.3 and 3.8 ML/ha, respectively of precipitation in the period between clearfells. We suggest A. donax has potential as a biomass crop on dryland, marginal soils in areas which receive over 450 mm of annual precipitation. If groundwater is available (even moderately saline) within 3 metres of the surface, A. donax roots are likely to access such subsoil waters to enhance yields. From the results of this project we classed A. donax in the premium group of crops for biomass yields, and carbon accumulation (high yields of harvested above ground carbon/ha/year). A. donax grown with wastewater irrigation, sequestered over 20 t/ha/clearfell year of carbon in the plant tops and maintained a similar amount in dynamic equilibrium in rhizomes (underground stems). If each tonne of sequestered carbon is valued at A$30, then this can generate A$600/ha for carbon stored in rhizomes in a dynamic equilibrium. Work undertaken by a commercial company (Pacific Pyrolysis) found that A. donax is a suitable material for commercial pyrolysis and biochar production and recommended further larger scale pilot tests be undertaken to obtain baseline data to design an efficient factory. Our results have shown that A. donax is a highly salt tolerant plant (halophyte) and can act as an interceptor crop to remove certain potential pollutants such as nitrogen and potassium from wastewaters and produce high yields under low or high nutrient regimes. Work with weed ecology experts indicated that A. donax had a negligible weed risk to terrestrial natural ecosystems (non riparian areas) of Australia, provided ongoing protocols (eg. site selection, buffer zones, basic crop hygiene and other practices) are put in place to prevent any spread to riparian areas. Conversely, A. donax was assessed as not suitable to be grown in riparian areas (less than 1 in 50 year flood risk), nor should it be allowed to spread to such areas in Australia. A. donax has the potential to produce up to 5 times more air dry pulp/ha/year (15.2 t) compared to Eucalyptus hardwoods (3.1t) when grown in southern Australia and irrigated with similar quantities of wastewater. A. donax appears suitable for making lower brightness and lower quality grades of tissues and with further optimisation, using the common kraft pulping process, it appears possible to make generic photocopier papers from A. donax. The kraft test results indicate that there is an opportunity to replace some of the imported eucalypt pulp with kraft pulped A. donax, as both are similar, short fibre pulps. Laboratory-scale studies with 10% (weight/volume) A. donax have demonstrated that up to 240 L of ethanol per oven dry tonne of A. donax can be produced with acid/enzyme hydrolysis and 224 L/dry tonne with alkali/enzyme pre-treatment. Future studies are needed for larger scale research, with optimised pre-treatment and fermentations, as well as conditioned micro-organisms. These techniques are likely to result in significant improvements in ethanol yields and productivities from A. donax of up to a total of 300-350 L/oven dry tonne of biomass (to match the best ethanol yields recorded per dry tonne, from cellulosic feedstocks to date). The cost of growing A. donax in the upper South East of SA, in the Meningie Downs area was assessed (allowing a 15% internal rate of return to the grower). At A$60/oven dry tonne at the factory gate and 500,000 oven dry tonnes supplied per year to a conversion factory, A. donax shows potential as a new industry for SA to produce either bioethanol and lignin, or pulp/paper, provided 3 years of near-market agronomy research and development and upscaling is funded and conducted. Preliminary estimates indicate an internal rate of return on funds employed of 22% per annum for the bioethanol

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and lignin enterprise and 18% per annum for the pulp/paper enterprise, based on central price estimates. It is expected that the commercial potential of non food, lignocellulosic crop feedstocks grown on marginal lands for conversion to biofuels will increase in future if the price of fossil fuels rises significantly, as is expected. Implications for relevant stakeholders The implications for industry are most encouraging. Internationally, there is major funding for developmental research into second generation biofuels, a limited number of new, commercial scale factories and growing interest in developing new second generation biofuel factories in Australia. They could provide breakthrough conversion technologies to lower the cost of lignocellulose conversion to biofuels. Australia has large areas of underutilised, cheap marginal lands and saline ground waters or low quality wastewaters. Australia has a modern, technologically-driven agricultural sector that could benefit from development of new regional industries based on non-food biofuel or pulp/paper crops. A. donax has good potential to be a major lignocellulosic feedstock, when grown in non riparian zones provided ongoing protocols are put in place to prevent any spread to riparian zones. A. donax, together with other lignocellulose feedstocks could form the basis of new biofuel and/or pulp/paper industries for Australia. Mining and food processing industries can also consider growing salt tolerant A. donax for disposal of moderately saline wastewaters on marginal lands in non riparian zones (using an integrated biosystem such as ‘serial biological concentration’) and producing lignocellulosic feedstock for biofuels or pulp/paper. Rural communities can explore the options for growing A. donax, a non-food, energy crop on underutilised land and using moderately saline water resources and benefit from job creation from new industries. Policy makers can use the information provided in this report to make informed decisions on biofuels and carbon credit policies (including emerging industry incentive schemes) to benefit Australia’s communities and industries in future. Recommendations This report forms the basis for obtaining baseline data, guidelines for agronomic systems, salt tolerance, weed risk management and potential biomass yields and carbon accumulation of A. donax grown for lignocellulosic feedstocks for biofuels or pulp/paper, on marginal or arable lands in dryland or irrigated biosystems. The report also provides preliminary estimates of indicative factory gate prices for A. donax, grown on different classes of land, and internal rates of return for enterprises producing bioenergy and other products or pulp/paper in SA. Further work needs to be undertaken on the following: 1. Verify the quality characteristics of A. donax biomass for ethanol or pulp/paper by conducting larger scale factory tests on the A. donax. 2. Assess overseas technology to convert A. donax biomass to bioethanol (within 16 hour time from factory gate to ethanol). Develop partnerships to progress options to develop bioethanol factories in Australia using A. donax and other plant lignocellulosic feedstocks for biofuels. 3. Determine the use of the waste ferment biomass mulch (up to 2,000 tonnes per day) from the bioethanol factory. This may have potential as a soil amendment in A. donax plantations. A number of research and development gaps have been identified.

xiii

•

Further work is needed to validate findings in small scale commercial plantations of A.donax of 5 hectare by 3 industrial biosystems, to upscale and demonstrate production systems developed in this report. The three proposed production systems are: dryland, roots self irrigated by the shallow water table and a saline, flood irrigation/drainage biosystem).

•

Develop pilot commercial systems of whole stem and/or rhizome plantings (based on the findings of Christou et al. 2000), with modifications to sugar cane planting and harvesting equipment to handle A. donax for large scale plantations, in non riparian zones of Australia.

•

Definition of the minimum nutrient and irrigation requirements of A. donax for target biomass yields for a range of environments. This should include assessment of wastewaters of different qualities on the survival and productivity of A. donax.

•

Plant species in Australia posing significant weed risks can be regulated through the various noxious weed Acts of the States and Territories. These are policy decisions for each government. As such it is not appropriate for this report to mandate a particular management approach. Rather, it is a guide for each State or territory to consider in determining their policy on A. donax. Each State interested in the potential cultivation of A. donax needs to develop a sound weed risk management policy (in the early stages of industry development).

•

It is desirable to obtain funds and conduct an international forum on: ‘Potential and barriers to develop A. donax and other lignocellulosic crops for biofuels or pulp/paper’. This would greatly facilitate the compilation of best practices and technologies to help establish new second generation biofuels industries.

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Introduction In Australia and most countries, increasing demands for high quality water resources, arable land, food and fossil fuels are greater than the sustainable, economic supply. This report presents research on the perennial, rhizomatous grass, giant reed (A. donax) for use on marginal lands (unsuited for food crops) with wastewaters or saline ground waters (or non-irrigated in areas with over 450mm annual precipitation) to produce lignocellulosic feedstocks (together with other biomass crops) to form the basis of new second generation biofuels and/or pulp/paper industries for Australia. The primary advantages of having a lignocellulosic biofuels industry are that the source materials are relatively cheap, domestically available, may not divert resources from food production, and they can be used to add value to existing rural industry processes (Warden and Haritos 2008). Globally, there is a growing need for cost effective, plentiful and low carbon dioxide emission transport fuels for industry and second generation biofuels could supply a portion of the global need (Warden and Haritos 2008). The biomass yields, carbon accumulation and biochar from A. donax are reported in Chapter 1, its salt tolerance and nutrient dynamics in Chapter 2, and weed risk management guidelines in Chapter 3, all to develop sustainable production systems. To provide new baseline data for industry, feedstock quality tests on A. donax are presented for pulp/paper in Chapter 4, for ethanol in Chapter 5 and potential economic returns in Chapter 6.

1

Objectives 1.

Overall, this project aims to produce baseline data to describe the biomass growth curves and nutrient uptake by the perennial grass, A. donax (giant reed) grown on saline, marginal land and arable land.

2.

Assess and report the yield and quality of A. donax biomass products from different production systems and their conversion efficiencies to biofuels or fibre. Compare such results for A. donax with that for other major crop options as reported in the literature, as feedstocks for biofuels (in Chapters 1, 5 and 6), for bioremediation (in Chapters 2 and 6) or for fibre/pulp/paper (in Chapters 4 and 6).

3.

Work with weed ecology experts (including Dr John Virtue, Department of Water, Land and Biodiversity Conservation and Dr Chris Preston, University of Adelaide) to conduct, for the Australian context, a formal weed risk assessment of A. donax and compile a weed risk management guidelines report (in Chapter 3).

4.

Assess via research conducted with Professor Peter Rogers (University of New South Wales) the pre treatment and fermentation for second generation ethanol production from A. donax (in Chapter 5).

5.

Conduct economic analyses, with Dr Ian Black, Principal Economist, SARDI, to estimate indicative factory gate prices for production of A. donax, on different classes of land and internal rates of return for enterprises producing bioenergy and other products or pulp/paper (in Chapter 6).

2

Methodology This report presents research on the potential and obstacles of growing A. donax (giant reed), on marginal lands and using wastewaters or moderately saline ground waters, to produce lignocellulosic feedstocks for biofuels and/or pulp/paper production. The methodologies utilised for each of the components of this project are detailed in the Materials and Methods sections of respective Chapters, and are summarised as follows: •

Plant yield and nutrient content data were used to calculate biomass yields, carbon accumulation and biochar from A. donax grown on marginal land and on arable soil, with varying irrigation regimes, (Chapter 1).

•

Data on salinity (ECswe) and nutrient concentration of soil water, together with crop evapotranspiration and plant and soil nutrient data were used to determine the salt tolerance and nutrient dynamics of A. donax (Chapter 2).

•

Weed ecology experts conducted a weed risk assessment using the South Australian Weed Management System (Virtue 2008) for future A. donax plantations in Australia (Chapter 3).

•

Two studies were commissioned to assess the feedstock quality of A. donax for pulp/paper, using two different methods. Central Pulp and Paper Research Institute, Saharanpur, India, assessed A. donax using the kraft pulping method and CSIRO Material Science and Engineering utilised the bisulphite pulping process (Chapter 4 and Appendices 4.A and 4.B respectively).

•

Laboratory-scale fermentation studies using both acid/enzyme and alkali/enzyme pre-treatments were undertaken to assess the potential for ethanol production (Chapter 5).

•

A preliminary economic analysis of production of A. donax on different classes of land and internal rates of return for conversion enterprises was undertaken. Details of the figures and assumptions used are documented (Chapter 6).

The results determined in Chapters 1, 2, and 3 are necessary to develop sustainable production systems for A. donax. The analyses and assessments reported in Chapters 4, 5 and 6 provide basic information the use of A. donax within the biofuels and pulp/paper industries.

3

Chapter 1: Dry matter yield, carbon accumulation and biochar from Arundo donax grown in South Australia by Chris Williams1, Tapas Biswas1, 2, Louise Chvyl1, Paul Harris3 and Chris Dyson1 1 SARDI, GPO Box 397, Adelaide, SA 5001, Australia, 2 Murray-Darling Basin Authority, GPO Box 1801, Canberra, ACT 2601 3 University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA 5064

Introduction More than 50 % of the cropped land in Australia is affected by soil acidity, sodicity and salinity problems with an estimated annual impact to the agriculture of over A$2,500 million (National Land and Water Resources Audit, 2002). Sustainable systems to use marginal land and waste waters for second generation biofuel or pulp/paper crops are urgently needed (Williams et al. 2007). The introduction of high-yielding, non-food biomass crops to support the change to renewable energy policy is inevitable. A. donax, commonly known as giant reed, has many relevant potential uses as feedstock for biofuels, pulp/paper or fodder production (Spafford 1941; Lewandowski et al. 2003; Paul and Williams 2006; Williams et al. 2006; 2008a). It is a perennial rhizomatous grass that has been present for over 150 years in Australia (Jessop et al. 2006). Williams et al. (2006; 2008b) reported A.donax produced exceptionally high biomass yields, of 51 t/ha of total dry matter yield of tops when harvested 43 weeks after clearfell (of a 30 year old stand) grown on arable land, irrigated with sewage effluent at Roseworthy, South Australia, and grown with no pesticides. Pathways for producing biofuels from A. donax are shown in Figure 1.1.

Potential pathways for biochar, biofuels Pyrolysis+ Use saline soils and saline wastewaters on

Bio- oil

pressure

Thermal treatment SALT TOLERANT GRASSES (eg Arundo donax ) , TREES

“Syngas ”

Organic wastes

Biochar: soil carbon store / C credit

Microbes or catalysts

Consolidated process (microbes Or enzymes)

Feedstock development SUNLIGHT

BIOMASS (smart breeding, genetic engineering)

MONOMERS

Biomass deploymerisation (microbes or enzymes)

FUELS

Biofuel production (microbes, enzymes or catalysts)

Algae Source: modified from The Economist, 2008

Figure 1.1: Potential pathways to convert cellulosic biomass to biofuels.

4

Giant reed, to put A. donax in its environmental context, is invasive in riparian systems of many regions of the world. The lack of fertile seed production limits spread of the reed via various seed dispersal mechanisms. Where stem and rhizome fragments are broken and dispersed by floodwaters, the species provides a significant weed threat. Based on the assumption that the appropriate planting sites are selected (eg. no plantations in riparian zones subject to flooding) and appropriate rigorous crop hygiene is employed (eg. use of buffer areas, covered transport), A. donax could be grown with a manageable level of risk (see Chapter 3; also Williams et al. 2006; 2008a; Pollock, Czako and Marton, unpublished data). This chapter describes the biomass production and carbon accumulation, pyrolysis and biochar characters of A. donax grown without pesticides on both arable and on marginal lands and examines potential roles for A. donax in Australian agriculture.

Materials and methods Field studies were conducted at the Roseworthy Campus (34˚ 52' S, 138˚ 69' E, altitude 68 m) of the University of Adelaide, South Australia. The climate of the region is typical of the southern Mediterranean-type environment, which consists of hot, dry summers and cool, wet winters. The experimental designs were blocks without replication, and subsamples were taken from each treatment to calculate means and indications of standard errors. An established, mainly dryland planting in a 90 m by 6 m block of A. donax of over 30 years in age, (‘old stand’) was divided into two blocks. The area was clear-felled to 10 cm on 7 June 2005 and 150 kg N/ha was surface applied. An irrigation regime using drippers was imposed from 16 January 2006 on a 60 metre portion of the block, (‘irrigated stand’) which had previously received some informal rainwater run-off, with the remainder never irrigated and termed ‘dryland stand’ (Table 1.1). For a supplementary study, rhizome sections of A. donax were planted at 5 rhizomes/m2 in a 40 m by 20 m block on 15 December 2005 (termed the ‘new planting’) and irrigation begun on 20 December 2005 (Table 1.1). Nitrogen was surface applied at 150 kg N/ha, 7 days before planting. The soil textures of the topsoils were loamy sand and medium clay at the old and new stands, respectively. The arable soils for the old stand and new plantings were a Calcareous, Regolithic, Red-Orthic Tenosol and a Sodic, Hypercalcic, Red Dermosol, respectively (Isbell 2002). Class 3 treated sewage effluent from the Campus residential area (reclaimed water) and pond treated dairy and pig effluent (recycled water) were used to irrigate the irrigated old stand and new planting, respectively (Table 1.1). Rates applied are given in the results section. At every clearfell A. donax plants were cut to 10 cm above soil level, per treatment. Plant yield, carbon and nutrient content and uptake were assessed from 3 to 5 quadrats of 0.5 or 1 m2 cut to 10 cm at each harvest. A total of 1 to 4 harvests of plant tops and rhizomes from the regrowth A. donax were conducted each year. Fresh weights of leaf and stem fractions were recorded and subsamples oven dried at 70˚C to determine dry matter content, yields, nutrient content and uptake. Plant and soil samples were analysed using procedures as described by Williams et al. (2004) and water by APHA (1998) methods. No pesticides were applied to A. donax during the conduct of these field experiments.

5

Table 1.1: Treatment details for experiments on arable soil at Roseworthy Treatment

Initiated

Method

Begin irrigation

Water source

Dripper spacing

Dryland old stand

7 June 2005

Clearfelled every 12-15 months

na

na

na

Irrigated old stand

7 June 2005

Clearfelled every 12-15 months

16 January 2006

Sewage effluent

75 * 50 cm#

New planting cut

15 December 2005

Rhizomes planted; then clearfelled every 12-15 months

20 December 2005

Pond-treated Dairy

100 * 50 cm#

New planting uncut

15 December 2005

Rhizomes planted; then left uncut

20 December 2005

Pond-treated Dairy

100 * 50 cm#

na=Not applicable #

Distance between polypipe lines of drippers then spacing between drippers in the line

The field site for studies on marginal land was a former salt evaporation basin near Barmera, SA (34° 14' S, 140° 35' E). The soil at the site was loamy sand overlying a sandy clay loam (pedology details in Appendix Table 1.A.1). The 1:5 soil:water Electrical Conductivity (EC) in the top 90 cm of soil ranged from 0.62 to 1.53 dS/m (saline soils). A. donax plantings were established by planting rhizomes from a nearby wild A. donax stand at Loveday, SA (Loveday rootstock) and a second rootstock from sandhills, approximately 100 metres from seawater at an Adelaide beach, Henley Beach, (Henley Beach rootstock). Rhizomes of both rootstocks were planted at 2-4 per linear metre in furrows 1 m apart (Williams et al. 2008b), (approximately 4 t/ha of rhizomes on an oven dry matter basis). The area was flood irrigated periodically with pond treated winery wastewater. The rates applied for each period of A. donax regrowth between clearfells are presented in the results section. Three to four harvests of plant tops and rhizomes were conducted each year to measure dry matter production and carbon accumulation, nutrient uptake and major salt elements, eg. sodium (Na) and potassium (K), with portions of both plantings remaining uncut. Plant, soil and water samples were analysed as per Williams et al. (2004) and APHA (1998). Climate data for both sites are presented in Appendix Tables 1.A.2 and 1.A.3. A sample of A. donax Loveday rootstock (stems with leaves) was sent to Pacific Pyrolysis, for batch pyrolysis tests to assess its suitability as a feedstock for commercial pyrolysis for heat, power and biochar production.

Results and discussion Plant and rhizome yield and carbon accumulation by A. donax at Roseworthy (a)

Clearfell old stand irrigated and dryland Total yield of A. donax plant top growth (leaf + stem) in the Roseworthy 30-year old stand, one year after the initial clearfell (CF), for the irrigated old stand was 45.4 t/ha of dry matter (DM), (Table 1.2). Thereafter this irrigated old stand at Roseworthy produced very high and consistent dry matter yields of plant tops of 58.4, 55.6, and 59.3 t/ha, respectively, each

6

clearfell year for the next 3 years (Table 1.2, Figures 1.2-1.5). For each of these 4 regrowth periods between clearfells (Table 1.2), irrigation rates applied were 17.9, 20.6, 13.5 and 14.7 ML/ha, respectively (plus precipitation of 5.3, 2.9, 3.8 and 2.3 ML/ha, respectively). The dry matter yields (Table 1.2) are higher than the range reported by Christou et al. (2001) and slightly greater than the highest yield sites reported in Angelini et al. (2005) and Lewandowski et al. (2003) in Europe. Christou et al. (2001) reported that the highest irrigated treatment (up to 14 ML/ha of irrigation plus approximately 5.6 ML/ha of precipitation/year) produced the densest stands and the highest yields, every year, of 24 to 30 t of dry matter/ha/year over 8 years of an annual clearfell regime. The ranges of A. donax yield results between countries are likely to be related to differences in genotypes, climate, soils, years, age of plantings, crop management and irrigation regimes. The relative quantity of carbon (C) sequestered in A. donax top growth and rhizomes (t C/ha/year) was closely related in relative terms to the A. donax top growth total dry matter yields (t/ha/year), (Tables 1.2, 1.3 and Figures 1.3 and 1.4). This was due to the carbon content of the plant organs being relatively constant: leaf, stem and rhizome C ranged from 41-47%, 38-47% and 43-49%, respectively on a dry matter basis (Chapter 2). Williams and Biswas (2009a) reported similar findings for the carbon content of A. donax organs in a series of pot trials conducted in a greenhouse. It is important to note that when the stand at Roseworthy, over 30 years old, was first clearfelled on 7 June 2005, to initiate the annual clearfell regime, 82.1 t/ha of oven dry green live stems plus 60.3 t/ha of dry dead stems were removed (Table 1.2). Moisture content of dead stems was less than 15% whereas green, live stems were over 40% moisture at all harvests. In our current work, after the initial clearfell harvest, for the 4 clearfell years to 2009, green live stems always made up over 95% of the biomass harvested. Therefore, regular annual clearfell harvest of A. donax irrigated plantations is likely to be an excellent strategy to reduce fire risk in dry seasons. If plantations of A. donax are left unharvested, significant quantities of accumulated very dry, dead stems could pose a far greater fire risk compared to annual clearfelled irrigated plantations. Experience in Texas confirms that significant amounts of dead stems of A. donax pose a high fire risk in dry seasons (Dr R Pollock, USA, pers. comm.). The dryland stand produced a total dry matter yield of A. donax tops of 12.6 t/ha one year after the first clearfell (Table 1.2). In subsequent clearfell years, the A. donax dryland stand produced dry matter yields of plant tops of 6.0, 12.9 and 6.7 t/ha, respectively (Table 1.2 and Figure 1.5). These yields were likely most dependent on precipitation which varied from 2.3 to 5.3 ML/period between clearfells, over the 4 years (Appendix Table 1.A.2). The long-term mean annual rainfall at Roseworthy is 440 mm. In similar rainfall periods, non-irrigated A. donax yields of 12.6 and 12.9 t/ha of dry matter tops (Table 1.2) surpassed total yields of 8 t/ha recorded for dense Wimmera ryegrass (Lolium rigidum) stands grown nearby on similar soils near Clare, SA (Williams and Allden 1976). Furthermore, carbon sequestered by the dryland A. donax old stand tops, 5.0 and 5.1 t/ha for 3.8 and 5.3 ML of precipitation in the clearfell periods 1 and 3 (Table 1.3), was far greater than the 2.83 and 2.98 t/ha/year for Eucalyptus cladocalyx (sugar gum) and Corymbia maculata (spotted gum), respectively, as reported by Paul et al. (2008) for whole tree biomass (tops plus roots) when mean annual rainfall was 5.1 ML for regions of southern Australia. Furthermore, for the same clearfell periods as above, the A. donax dryland stand had 6.2 to 7.5 t/ha of carbon sequestered in dynamic equilibrium, in rhizomes. Similarly, the harvested above ground carbon, for the dryland old stand, of 5.0 and 5.1 t/ha, for the clearfell periods 1 and 3, as above, were double the 2.5 t/ha/year of carbon in switchgrass tops grown on the fertile soils of the Great Plains, USA, which received the mean annual precipitation of 4.3 to 7.8 ML/ha (Liebig et al. (2008).

7

It is stressed that when the dryland portion of the 30 year old stand was first clearfelled, 18.6 t/ha of dead dry stems were removed (a potential fire risk) along with the 10.1 t/ha of green, live stems (Table 1.2). This portion of the 30 year old stand had no previous irrigation. Once the clearfell regime was imposed, on the dryland old stand, negligible numbers of very dry, dead stems were harvested, only green live stems with over 40% moisture content. The stems in the irrigated old stand were higher, greater in girth, more numerous and with greater dry weight per stem than the stems in the dryland stand but had similar % dry matter (Table 1.4). Stems produced in the new planting (irrigated), after 6 months were similar in the above characteristics to those in the non-irrigated treatment of the established stand after 1 year regrowth from clear fell. Christou et al. (2001) recorded that the stems of highly irrigated plants were significantly longer and thicker than the stems of the non-irrigated plants in most years. A rhizome of A. donax is a creeping stem, usually horizontally, at or under the surface of the soil and differing from a root in having scale leaves, or shoots near its tips, and producing roots from its under surface (McClure 1993). Rhizomes may also be referred to as rootstocks. For the old stand, we discovered that once the clearfell regime was imposed, the rhizome dry matter yields/ha/clearfell period came into dynamic equilibrium. This varied from 46.6-69.3 and 16.5-25.2 t/ha/clearfell, respectively, for the irrigated and dryland old stands, respectively (Table 1.2, Figures 1.4 and 1.6). We suggest that the water supply to the A. donax plants was the most likely major determinant of the rhizome yield equilibrium levels achieved in a given environment and crop clearfell regime. Organic carbon in rhizomes only ranged from 43-49% (Chapter 2). The rhizomes contained organic carbon between 20.5-30.5 and 6.2-10.8 t/ha/clearfell period, for the irrigated and dryland old stands, respectively (Table 1.3 and Figure 1.6). . (b)

Irrigated new planting, clearfell and uncut The total yields of dry matter (DM) of top growth of A. donax from the new planting at Roseworthy at each clearfell (CF) were, 31.1, 40.2, 9.2 and 23.0 t/ha, respectively (Figure 1.7). For each of these 4 regrowth periods between clearfells, wastewaters applied by irrigation were 15.9, 9.5, 4.4 and 6.3 ML/ha, respectively, (plus precipitation of 2.8, 1.9, 3.8 and 2.3 ML/ha, respectively). The variations in top yields (Figures 1.7-1.10) were most likely due to variable irrigation rates due to reduced supplies of wastewaters, the onset of drought conditions and the unplanned grazing by cattle. Top growth standing yields from the uncut, new planting at Roseworthy (Table 1.1) varied from 31.1 to 23.8 t/ha of dry matter at each sampling. Rhizome dry matter yields were in the range of 17.5 to 47.7 t/ha, during the same period (Table 1.10). The carbon content of A. donax organs was relatively constant, with leaf, stem and rhizome contents ranging from: 4148, 41-48 and 44-49%, respectively, on a dry matter basis (Chapter 2). The quantities of carbon sequestered by each organ were closely related in relative terms to the dry matter yields of that organ (Figures 1.7-1.10).

8

Table 1.2: Dry matter (DM) biomass yields (t/ha) at Roseworthy at each clearfell for the A. donax old stand (first clear felled 7/06/2005 after 30 years). Standard error of the mean is shown in parentheses.

Days Leaf Green Stem Tops# Rhizome from CF Irrigated CF 7/06/2005# 0 7.2 (1.4) 82.1#(19.1) 89.3#(31.8) 74.6 (17.2) Dryland CF 7/06/2005# 0 1.0 (0.2) 10.1 (2.5) 11.1 (4.2) 51.8 (8.4) Irrigated CF 5/06/2006 356 7.7 (1.1) 37.7 (5.6) 45.4 (6.6) 69.3 (26.3) Dryland CF 5/06/2006 356 2.3 (0.6) 10.3 (2.6) 12.6 (3.2) 23.3 (4.6) Irrigated CF 5/06/2007 365 9.7(4.4) 48.7 (18.7) 58.4 (23.1) 46.6 (20.4) Dryland CF 5/06/2007 365 1.8 (0.3) 4.2 (0.7) 6.0 (1.0) 16.5 (2.7) Irrigated CF 3/09/2008 456 4.1 (0.2) 51.5 (25.5) 55.6 (25.7) 50.9 (2.2) Dryland CF 3/09/2008 456 2.2 (0.6) 10.7 (4.3) 12.9 17.4 (3.2) Irrigated CF 26/06/2009 296 4.6 (1.3) 54.7 (16.4) 59.3 (17.7) 58.8 (6.9) Dryland CF 26/06/2009 296 2.7 (0.4) 4.0 (0.7) 6.7 (0.5) 25.2 (6.5) # At the initial clearfell after over 30 years growth, 7/06/2005, 60.3 t/ha of dead stems were removed but not included in the green, live tops total yield. Treatment/ Date

Table 1.3: Organic carbon (t/ha) sequestered at Roseworthy at each clearfell, from the A. donax old stand (first clearfelled 7/06/2005).

Treatment/ Date Irrigated CF Dryland CF Irrigated CF Dryland CF Irrigated CF Dryland CF Irrigated CF Dryland CF Irrigated CF Dryland CF

7/06/2005 7/06/2005 5/06/2006 5/06/2006 5/06/2007 5/06/2007 3/09/2008 3/09/2008 26/06/2009 26/06/2009

Days from CF 0 0 356 356 365 365 456 456 296 296

Leaf 3.5 0.4 3.2 1.1 4.7 0.8 1.9 1.0 2.2 1.2

Green Stem 38.8 (13.2) 4.5 (2.2) 17.5 3.9 21.9 1.6 23.2 4.1 24.6 1.5

Tops 42.3 4.9 20.7 5.0 26.6 2.4 25.2 5.1 26.8 2.8

Rhizome 35.6 (16.0) 26.7 (4.2) 30.5 6.2 20.5 7.1 22.4 7.5 25.9 10.8

Figure 1.2: A. donax, old stand, 361 days after first clear fell, left: Dryland and right: Irrigated treatments at Roseworthy.

9

b)

100

60

80

50 C (t/ha)

DM (t/ha)

a)

60 40 20

40 30 20 10

0

0

0

1

2

3

4

0

Years from initiation

1

2

3

4

Years from initiation

Figure 1.3 a, b: Dry matter (DM) and organic carbon (C) yields of A. donax top growth, at Roseworthy old stand, irrigated clearfell (CF) treatment, 2005 to 2009.

b)

80 70 60 50 40 30 20 10 0

C (t/ha)

DM (t/ha)

a)

0

1

2

3

4

40 35 30 25 20 15 10 5 0 0

1

2

3

Years from initiation

Years from initiation

Figure 1.4 a, b: Dry matter and organic carbon yields of A. donax rhizomes, at Roseworthy old stand, irrigated CF sites, 2005-2009

10

4

a)

b) 10

C (t/ha)

DM (t/ha)

20

10

0

5

0

0

1

2

3

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0

Years from initiation

1

2

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4

Years from initiation

Figure 1.5 a, b: Dry matter and organic carbon yields of A. donax tops, at Roseworthy old stand, dryland CF sites, 2005-2009.

b)

60

30

50

25

40

20

C (t/ha)

DM (t/ha)

a)

30 20

15 10

10

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0

0

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Years from initiation

1

2

3

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Years from initiation

Figure 1.6 a, b: Dry matter and organic carbon yields A. donax rhizomes, at Roseworthy old stand, dryland CF sites, 2005-2009. Table 1.4: Stem height, diameter, number, dry weight and percent dry matter for 5 June 2006 clearfell harvest at Roseworthy. Standard error of the mean is shown in parentheses.

Treatment Old stand Dryland Irrigated New planting Irrigated

Height (cm)

Diameter (mm)

Number of stems (per m2)

Stem dry weight (g/stem)

Dry matter (%)

224 (41) 422 (38)

16.2 (2.9) 22.0 (2.9)

17.3 (1.6) 22.0 (3.8)

36.9 (5.2) 61.7 (5.5)

43.4 (0.7) 44.1 (1.1)

233 (115)

14.3 (6.4)

26.4 (5.0)

46.1 (10.3)

41.2 (0.2)

11

b)

45 40 35 30 25 20 15 10 5 0

25 20 C (t/ha)

DM (t/ha)

a)

15 10 5 0

0

0.5

1

1.5

2

2.5

3

0

3.5

0.5

1

1.5

2

2.5

3

3.5

Years from planting

Years from planting

Figure 1.7 a, b: Dry matter and organic carbon yields of A. donax tops, at Roseworthy, new planting, CF sites, 2006-2009.

b)

20

35 30 25 20 15 10 5 0

15 C (t/ha)

DM (t/ha)

a)

10 5 0

0

0.5

1

1.5

2

2.5

3

3.5

Years from planting

0

0.5

1

1.5

2

2.5

3

3.5

Years from planting

Figure 1.8 a, b: Dry matter and organic carbon yields of A. donax rhizomes, at Roseworthy new planting, CF sites, 2006-2009.

12

b) 60

30

50

25

40

20

C (t/ha)

DM (t/ha)

a)

30 20

15 10

10

5

0

0 0

0.5

1

1.5

2

2.5

3

0

3.5

0.5

1

1.5

2

2.5

3

3.5

Years from planting

Years from planting

Figure 1.9 a, b: Dry matter and carbon yields of A. donax tops, at Roseworthy, new planting, uncut sites, 2006-2009.

b)

60

25

50

20

40

C (t/ha)

DM (t/ha)

a)

30 20

15 10

10

5

0

0 0

0.5

1

1.5

2

2.5

3

3.5

0

0.5

1

1.5

2

2.5

3

3.5

Years from initiation

Years from planting

Figure 1.10 a, b: Dry matter and carbon yields of A. donax rhizomes, at Roseworthy new planting, uncut sites, 2006-2009.

Plant and rhizome yield and carbon accumulation by Adx at Barmera (marginal land) One year after planting at Barmera, the flood irrigated Loveday rootstock of A. donax produced 45.2 t/ha of total above ground biomass (including 20.6 t/ha of carbon sequestered) at the first clearfell (Tables 1.5 and 1.6, Figure 1.12). In comparison, the Henley Beach rootstock produced 29 t/ha of dry tops (including 13.7 t/ha of carbon), (Figure 1.12, Tables 1.5 and 1.6).

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Carbon sequestration is the uptake and storage of atmospheric carbon in, for example, soils and vegetation. Photosynthesis by A. donax during the first year was the likely main mechanism for the large amounts of organic carbon accumulated, namely 20.6 and 12.0 t/ha in the dry tops and rhizomes, respectively, for the Loveday rootstock (Table 1.6). The Loveday rootstock at Barmera, under the clearfell regime produced high dry matter yields of plant tops of 45.2, 35.0 and 28.8 t/ha, respectively, at each clearfell harvest over 3 years (Table 1.5, Figures 1.11 and 1.12). In comparison, the Henley Beach rootstock produced yields of dry tops of 29, 12.8, and 10.8 t/ha over the same periods. The differences from year to year within a rootstock could be due to reduced irrigation rates due to reduced supplies of wastewaters. For each of these 3 regrowth periods between clearfells, wastewaters applied by irrigation were, 21, 16.7 and 12.6 ML/ha, respectively, (in addition there was a recorded precipitation of 2.2, 2.5 and 1.1 ML/ha, respectively). Carbon accumulation by the 2 rootstocks reflected, in relative terms, the differences in dry matter yields (Table 1.6, Figure 1.12). Differences between these two rootstocks were likely due to genetic and/or genotype by environment interactions. For example, yields of dry rhizomes for the Loveday and Henley Beach Adx rootstocks were 26.6, 40.8 and 44.9 and 16.3, 10.0 and 8.7 t/ha, over the three year period (Table 1.5 and Figure 1.13). These variations in top growth and rhizome yields were likely due to the onset of drought conditions and restricted irrigation rates in years 2 and 3 (16.7 and 12.6 ML/ha of wastewaters applied) compared to 21 ML/ha in the first year. The Loveday rootstock produced higher rhizome yields of dry matter in years 2 and 3, compared to the Henley Beach rootstock. This correlated with the higher top growth yields of the Loveday rootstock at all harvests (Tables 1.5, 1.6 and Figures 1.12 and 1.13). The sections of the A. donax rootstocks left uncut for three years at Barmera, reached top growth yields of 32.8 to 48.6 for the Loveday rootstock and 6.0 to 29 t/ha for the Henley Beach rootstocks (Figure 1.14). Each rootstock in the uncut treatment, also reached a maximum yield for rhizome dry yields and carbon sequestered in top growth and rhizomes (Figures 1.14 and 1.15). Total yields for A. donax will vary with differences in irrigation inputs, harvest regimes, climate and management conditions. Dead, dry stem yields for the Loveday rootstock, at the final harvest at Barmera were 8.4 and 9.8 t/ha, respectively for the uncut and clearfell stands, respectively. This may be due to to the cumulative effects of the high Biological Oxygen Demand (BOD) of the applied wastewaters (over 4000 mg/L), having an impact on stem growth and survival (refer to Chapter 2). Growth cycle of A. donax in South Australia Each year for all field experiments reported in this project, new shoots of A. donax emerged August to September (early spring at the Southern Hemisphere latitude of 350S), the stems and leaves then grew rapidly to reach maximum growth rates during December and January (mid summer at these sites), (growth curves in Figures 1.3-1.15). Crop growth rates declined in autumn (March to May, in the Southern Hemisphere), with nil to very limited growth in the mid winter months (June, July). In the Northern Hemisphere, at a higher latitude of 430N, Angelini et al. (2009) reported that in winter time A. donax plants stop their growth because of low temperatures and regrowth occurs the following spring. However, we found that only when severe frosts occurred, as observed at the Barmera site in 2008, did plant growth stop and significant leaf mortality occur.

14

*

Table 1.5: Dry matter (DM) biomass yields at Barmera CF at each clearfell . Standard # error of the mean is shown in parentheses

Adx rootstock Loveday Henley Beach Loveday Henley Beach Loveday Henley Beach #

Date 16/05/2007 16/05/2007 20/08/2008 20/08/2008 22/04/2009 22/04/2009

Biomass yield (t/ha/year) Days Leaf Stem Tops from CF * 365 9.3 (2.1) 35.9 (3.4) 45.2 (3.5) 356* 11.3 (4.9) 17.7 (6.6) 29 .0 (10.7) 462 0.8 (0.3) 34.3 (12.9) 35.0 (13.2) 462 0.3 (0.2) 12.6 (1.8) 12.8 (1.7) 245 5.9 (0.5) 22.9 (4.6) 28.8 (5.1) 245 3.3 (0.5) 7.52 (0.7) 10.84 (0.3)

Rhizome 26.6 (5.4) 16.3 (7.8) 40.78 (6.8) 10.04 (1.0) 44.9 (10.0) 8.73 (0.1)

Trials planted 16 May 2006 at Barmera, South Australia *

Table 1.6: Organic carbon sequestered at Barmera CF at each clearfell . Standard error # of the mean is shown in parenthesis .

Organic carbon yield (t/ha/year) Adx rootstock Loveday Henley Beach Loveday Henley Beach Loveday Henley Beach #

Date 16/05/2007 16/05/2007 20/08/2008 20/08/2008 22/04/2009 22/04/2009

Days from CF 365* 365* 462 462 245 245

Leaf 4.1 (0.9) 5.3 (2.4) 0.4 (0.1) 0.2 (0.1) 2.8 (0.3) 1.4 (0.2)

Stem 16.5 (1.4) 8.4 (3.2) 17.6 (7.1) 6.2 (1.0) 9.2 (1.8) 3.4(0.3)

Tops 20.6 (1.4) 13.7 (5.0) 17.8 (7.2) 6.4 (1.0) 11.9 (2.0) 4.8 (0.1)

Rhizome 12.0 (2.5) 7.3 (3.5) 20.4 (4.1) 4.8 (0.6) 19.8 (3.0) 3.8 (0.1)

Trials planted 16 May 2006 at Barmera, South Australia

Figure 1.11: Left: Loveday rootstock of A. donax in marginal soil at Barmera, 5 months after planting, October, 2006; Right: same A. donax at first clearfell, June 2007 (yield 45.2 t/ha dry tops).

15

b)

50

25

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20 C (t/ha)

DM (t/ha)

a)

30 20

15 10

10

5

0

0

0

1

2

3

0

0.5

Years from planting

1

1.5

2

2.5

3

Years from planting

Figure 1.12 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax tops at Barmera for the annual clearfell treatments for the Loveday (▲) and Henley Beach rootstocks (•) over 3 years to 2009.

b)

50

25

40

20 C (t/ha)

DM (t/ha)

a)

30 20

15 10

10

5

0

0

0

1

2

3

Years from planting

0

1

2

3

Years from planting

Figure 1.13 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax rhizomes at Barmera for the annual clearfell treatments for the Loveday (▲) and Henley Beach rootstocks (•) over 3 years to 2009.

16

b) 50

25

40

20

30

15 C (t/ha)

DM (t/ha)

a)

10

20 10

5

0

0

0

1

2

0

3

1

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3

Years from planting

Years from planting

Figure 1.14 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax tops at Barmera for the annual uncut treatments for the Loveday (▲) and Henley Beach rootstocks(•) over 3 years to 2009.

b)

50

25

40

20

30

C (t/ha)

DM (t/ha)

a)

20 10

15 10 5

0

0

0

1

2

3

Years from planting

0

1

2

3

Years from planting

Figure 1.15 a, b: Dry Matter (DM) and organic carbon (C) yields of A. donax rhizomes at Barmera for the annual uncut treatments for the Loveday (▲) and Henley Beach rootstocks (•) over 3 years to 2009.

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Pyrolysis and biochar from A. donax Results for pyrolysis tests conducted and reported by Pacific Biochar, including biochar yields from A. donax, are presented verbatim in Appendix 1.B. They concluded that A. donax is a suitable material for commercial pyrolysis and biochar production and it is recommended that further larger, pilot scale tests be undertaken to allow more detailed information to be gathered to meet future needs to design an efficient, full scale factory for combined heat and power and biochar (Appendix 1.B). Comparison of biomass species as pulp or energy crops and potential of A. donax Using results from year one of trials reported in this project, Paul and Williams (2006) estimated that A. donax irrigated with wastewaters has potential to produce up to 5 times the air dry pulp yield per hectare per year compared to Blue gum (Eucalyptus globulus) hardwood trees, when grown in South Australia (based on 40 t/ha of oven dry stems produced by Adx per annum). In subsequent years at Roseworthy, 2007-2009, irrigated A. donax produced from 48.7-54.7 t/ha/clearfell period of oven dry stems (Table 1.2). These results indicate that A. donax is a promising alternative to conventional non wood pulp/fibre options. Other fibre crops, such as kenaf (Hibiscus cannabinus) which produced a peak dry matter yield of 25.6 t/ha with irrigation in the Ord Irrigation Area, Western Australia, (Wood 1978), required from 5 to 29 sprays of insecticide per growing season, to prevent plants being defoliated by insects. Perennial grasses have many beneficial traits as energy crops (Lewandowski et al. 2003). A. donax with the C3 photosynthetic pathway was found to produce 34.8% higher dry matter yields compared to Miscanthus x giganteus (hybrid), a C4 grass (Table 1.7), in field trials in Italy over 11 years (Angelini et al. (2009). Low winter temperatures and shorter growing seasons are major limits to the growth of C4 grasses in southern Australia (Williams et al. 2009) and northern Europe (Lewandowski et al. 2003). Switchgrass (Panicum virgatum), favoured in some regions, a native to north America, usually produces lower biomass yields/ha/year, when compared to the above 2 grasses under the same conditions (Lewandowski et al. 2003, Dr R. Pollock, USA, pers. comm.). Table 1.7: Maximum yield, net energy, fuels/year (mean value from the second to the twelfth year of growth, Italy).

Treatment

Yield (t/ha)

Net Energy (GJ/ha)

Petrol Equiv. (t/ha)

Coal Equiv. (t/ha)

A. donax 37.7 637 14 20 (Adx) Miscanthus x 28.7 467 10 15 giganteus (hybrid) Advantage of 34.8 36.4 40 33.3 Adx (%) Source: Angelini et al. (2009), Central Italy, 857mm rainfall and water table at 120cm deep during the driest periods. To evaluate the performance of A. donax and Miscanthus x giganteus in agricultural production systems as bioenergy crops, Angelini et al. (2009) calculated the net energy yield (energy output minus energy inputs/ha) and energy production efficiency (the ratio between energy output and input/ha). Their results showed that 1 ha of A. donax produced net energy of 637 GJ/ha and could substitute for 14 t/ha and 20 t/ha of petroleum and coal, respectively (Table 1.7). Such yields surpassed those from M. giganteus by over 25% per annum (Table 1.7) grown under the same conditions. They also calculated annual crops require approx. 50% of the total energy produced for production; whereas A. donax requires only 1.9% and Miscanthus 2.6%/year.

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Efficient production of pulp/paper or bioenergy from such perennial grasses requires selection of the most appropriate grass species for the given growing region/climatic/management conditions (Lewandowski et al. 2003), and selection to meet target yields and quality criteria within the framework of sustainable, profitable production systems. Since research on perennial rhizomatous grasses is recent, there are significant gaps in the knowledge base and further work is needed.

Conclusions Introduction of high yielding, high carbon, non-food biomass crops to support the change to renewable energy policy is desirable. When compared to data presented in the literature in relation to other biomass species, A. donax produces more cellulosic biomass and sequesters more carbon per annum, under SA conditions. It should be noted that the reports in the literature are for biomass grown under warm temperate to sub tropical temperature on marginal lands with similar water input regimes (either irrigated with wastewaters or grown dryland with over 450 mm of annual precipitation). A. donax produced the high biomass yield of 45.2 t/ha of dry tops in the first year, when grown on saline, marginal land at Barmera with winery wastewater. On arable soil at Roseworthy, A. donax produced 45.4, 58.4, 55.6 and 59.3 t/ha/year of dry tops each clearfell year, when irrigated with reclaimed sewage. The non irrigated, clearfell Adx treatment at Roseworthy produced 12.6 and 12.9 t/ha of dry tops with 5.3 and 3.8 ML of precipitation in the periods between clearfells, respectively. These biomass yields consisted of 5.0 and 5.1 t/ha of harvested above ground carbon (carbon sequestered in plant tops), which was double that produced by switchgrass grown on fertile soils of the Great Plains, USA, with annual precipitation of 4.3 to 7.8 ML (Liebig et al. 2008), and greater than that of sugar gums grown in southern Australia (Paul et al. 2008). We suggest A. donax has potential as a biomass crop on dryland, marginal soils in areas which receive over 450 mm (4.5 ML) of annual precipitation. If groundwater is available within a few metres of the surface, A. donax roots are likely to access such subsoil waters to enhance yields (Angelini et al. 2009). From the results of this project we classed A. donax in the premium group of crops for carbon sequestration (including high yields of harvested above ground carbon per ha per annum) and carbon credits, when irrigated with wastewaters, as it sequestered over 20 t/ha/year of carbon in plant tops and maintained a similar amount in dynamic equilibrium in rhizomes (underground stems). If each tonne of sequestered carbon is valued at A$30, then it will generate some A$600/ha for carbon stored in rhizomes in a dynamic equilibrium. Furthermore, carbon stored in the true root system of A. donax, in addition to the rhizomes, needs to be assessed in future. Preliminary calculations by Paul and Williams (2006) indicated that giant reed has the potential to produce up to 500 per cent more air dry pulp per ha per year (15.2 t) compared to Eucalytus hardwoods (3.1 t) when grown in southern Australia. Further research is required to obtain data on the long term productivity of giant reed (assuming a plantation life of 20-35 years) and to define irrigation, wastewater quality, nutrient requirements and other best management practices for sustainable systems. A. donax produced up to 45.2 t/ha per year of dry tops on the saline, marginal soils at Barmera (with wastewater irrigation). This grass, a wetland monocot, could form the basis of a new industry producing biofuels and/or pulp/paper, using saline, marginal soils and moderately saline wastewaters in southern Australia. Further research is needed to upscale and demonstrate/verify production systems and methodologies developed in this report, as well as pilot commercial systems of whole stem and/or rhizome plantings (based on the findings of Christou et al. 2000), and mechanisation of planting and harvesting equipment to handle A. donax. The three proposed production systems are: dryland, saline self- irrigation, flood irrigation/drainage biosystem (further descriptions in Chapters 2 and 6).

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Chapter 2: Salt tolerance and nutrient dynamics of Arundo donax Chris Williams1, Tapas Biswas1, 2, Louise Chvyl1 and Chris Dyson 1 1 SARDI, GPO Box 397 Adelaide, SA, 5001 2 Murray-Darling Basin Authority, GPO Box 1801 Canberra, ACT 2601

Introduction Salt in irrigation waters and subsoils is often associated with the elevation over time of the salt content of the rootzone, which in turn results in reduced crop biomass yields (Lazarova and Bahri 2005). An aim of research reported in this chapter is to define the salt tolerance and nutrient removal by A. donax and to develop guidelines for the beneficial use of highly saline wastewaters for irrigation (eg. reuse of some Salt Interception Scheme (SIS) wastewaters) on marginal lands. Soil salinity refers to the concentration of dissolved salts in the soil solution. The soluble salts in soils predominantly consist of the cations: sodium (Na), calcium (Ca), magnesium (Mg), potassium (K) and the anions: chloride (Cl), nitrate (NO3), sulphate and bicarbonate. Soil salinity levels are usually determined by measuring the electrical conductivity (EC in deci Siemens/metre, dS/m) of a soil suspension, which estimates the concentration of soluble salts in the soil at a given depth sampled. High EC values, corresponding to high concentrations of soluble salt in soil, are undesirable as they reduce normal growth and yield of most plant species and also restrict land use options and may lead to increased soil erosion. With increased irrigation efficiency comes the greater risk of increased salt, nutrient and other chemical accumulation within the crop root zone. Knowledge of soil water composition in the root zone is crucial for sustainable irrigation, especially when wastewater is used. By using a SARDI soil water extractor (SoluSAMPLERTM , Biswas 2006) and analysing the extracted solution for salinity and nutrients, it is possible to monitor whether salt and/or nutrients are accumulating in the root zone and then to adjust irrigation or fertiliser practices to develop sustainable irrigation and nutrient systems for Adx crops. Lewandowski et al. (2003) in their review of grasses grown for biomass in Europe, state that A. donax is salt tolerant, but provide no evidence for this claim or neither do they discuss the degree of salt tolerance of the plant. Similar statements were made in the paper on A. donax by the former Director of Agriculture in South Australia, (Spafford 1941. The first objective of this study was to define the salt tolerance of A. donax and gain an understanding of nutrient dynamics when A. donax was grown on saline, marginal land with winery wastewater on a former salt evaporation basin near Barmera, SA (34O 14’ S, 140O 35’E). The second aim was to describe the content and uptake of nutrients by A. donax crops grown under saline and non-saline regimes in order to develop sustainable nutrient management strategies for the maintenance of economic yields of biomass to provide a stable feedstock supply.

20

Materials and Methods Design and layouts of the field studies on A. donax conducted on the former salt pan site near Barmera, (saline soil) and on arable land at Roseworthy, SA have been described in Chapter 1 (Materials and Methods). The electrical conductivity (ECswe) of 1:5 soil:water extracts of root zone soils at Barmera ranged from 0.62 to 1.53 dS/m (indicating saline soils). Salinity (as ECswe) and nutrient concentrations of the soil water extracts were assessed at Barmera using especially designed SARDI soil water extractors installed at 30, 60 and 90 cm soil depths in the centre of the ridge of the planting row. The soil water extractor is a porous ceramic suction cup device, which can sample soil water after a suction of 60-70 kPa is applied (Biswas 2006) down an access tube using a simple syringe and Luer lock device. The vacuum draws the moisture from the surrounding (unsaturated) soil into the inert ceramic cup which can then be brought to the soil surface for measuring its salinity and nutrient content (Biswas et al. 2007). Soil water extract samples were collected from the permanently installed soil water extractors (at c. 13 month intervals) from August 2006 to April 2009 at the Barmera site. These samples (volumes of 10–50 ml) were used to measure EC with a Hanna meter and pH with a pH meter, and then frozen. The frozen samples were sent to CSIRO, Land and Water, Analytical Chemistry Lab, Urrbrae, Waite Research Precinct for nutrient, chloride and metal analyses. Methods used for analysing water samples were as described by APHA (1998). Crop evapotranspiration (ETo) was calculated from the modified Penman-Monteith equation as described by Allen et al. (1998). Soil samples from depths of 0-30, 30-60, 60-90cm were collected in June 2005 and June 2009 to measure changes in soil nutrients over time. These data contributed to an assessment of sustainability indicators and of related issues. Plant and soil samples were analysed using procedures as described by Williams et al. (2004).

Results and Discussion Chemical composition of influent wastewater The chemical composition of the winery wastewaters in the holding lagoon used to irrigate the A. donax crops at the Barmera saline soil site are shown in Appendix Tables 2.A.1 to 2.A.4. According to the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC 1999), irrigation water with a salinity of EC 800 uS/cm (equals 0.8 dS/m) is considered saline, and irrigation water with an EC >2.4 dS/m is highly saline and considered not suitable for irrigation under ordinary conditions for traditional crops (eg. cereals, citrus, vegetables). This is due to the expected induced salinisation of soils and the reduction in yield of most traditional crops under normal conditions of highly saline influent irrigation systems (Peverill et al. 1999; Shaw 1999). The high dry matter yields of top growth produced by the Loveday rootstock stand of A. donax of up to 45.2 t/ha/year under the annual clearfell regime (Chapter 1), over 3 years, under the saline influent irrigation regime, indicated a potential high salt tolerance of Adx under the field conditions of this study at Barmera. Electrical conductivity (ECse) of the soil paste saturated extract of between 2-4 dS/m indicated yields of salt sensitive crops is most likely to be significantly reduced (Biswas and Higginson 1998). The treated winery influent wastewater (hereafter termed recycled water) used to irrigate the A. donax stand at Barmera was usually very low in nitrate (<0.5 mg N/L) but had moderate ammonia concentrations (<1 up to 12 mg N/L) for A. donax growth (Tables 2.A.1 to 2.A.4). The total N concentration of 23.7 mg/L and non purgeable organic carbon (NPOC) of 61.3 mg/L when measured on 16 October 2006 in addition to the above ammonium N results indicated that the recycled water applied could supply much of the N requirement for growth of the A. donax crop (Tables 2.A.12.A.4). In the recycled influent of other macronutrients, total phosphorus (P) concentrations (0.5 – 38.5 mg/L) were moderate to high for plant growth, and it is likely that influent P provided much of the total P requirements for A. donax growth at Barmera and Roseworthy (Tables 2.A.2 to 2.A.5). Concentrations and amounts of potassium (K), in influent irrigation (140-5530 and 5-122 mg/L at

21

Barmera and Roseworthy, respectively) were likely to be high to excessive for A. donax growth (Tables 2.A.2-2.A.5). A. donax was very tolerant to these high potassium regimes when adequate irrigation was applied as the plant produced consistent, very high yields of dry matter per hectare per year under these conditions (Chapter 1). Furthermore, the high K regimes would likely assist the A. donax plant to maintain internal cation balance and restrict sodium uptake (Flowers et al. 1986; Williams et al. 2009). Concentrations of certain other nutrients in the influent irrigation such as: calcium (Ca), magnesium (Mg), sulphur (S), boron (B), copper (Cu) and zinc (Zn) were such as to likely supply the majority of the requirements for normal growth of A. donax. Soil water rootzone salinity and salt tolerance of A. donax Changes in salinity within the root zone, in the first year, in terms of the Electrical Conductivity of the soil water extracts (ECswe) within the Loveday and Henley Beach rootstocks plantations of A. donax at Barmera are presented in Figures 2.1 and 2.2. The A. donax plants produced high dry matter biomass yields of total tops of 45.2 and 29.0 t/ha, respectively, in the first year when exposed to similar ranges of salinity (ECswe), (Figures 2.1 and 2.2). Electrical conductivity values of soil water extracts (ECswe) for the Loveday stand of A. donax were less than 10 dS/m at 60 and 90 cm soil depths from August, 2006 to the end of December, 2006 (Figure 2.1a). For the Loveday stand, after January 2007, there was a dramatic increase in ECswe up to levels of 25-50 dS/m by April, 2007, which then declined with winter rainfall (leaching salt) to levels of 17-30 dS/m by end of June, 2007, the end of year 1 of this project. The Loveday rootstock was exposed to a similar range of soil water salinity in the rootzone (3.1 to 47.8 dS/m) as in year 1 in the period from January 2008 to March 2009 (Table 2.1). However, the Henley Beach rootstock was exposed to a lower salinity range (ECswe of 3.2 to 20.6 dS/m) over the latter period (Table 2.1). The importance of periods of precipitation to reduce salts in the root zone by leaching, either where salts are inadvertently added by the use of saline irrigation or on saline soils directly is stressed. It is important to note that salinity of the open ocean water has an EC of approximately 55 dS/m. Ayers and Westcot (1989) reported crop salinity tolerance ratings. They classed crops which were exposed to salinity of the soil extract, ECse > 10 dS/m equivalent to soil water extract, ECswe, > 20 dS/m as extremely salt tolerant, as this was extremely high salinity at which first signs of yield loss may occur in such crops, whereas it was unsuitable for most crops. Date palm (Phoenix dactylifera) classed as a salt tolerant crop, incurred a 50 % yield reduction when the salinity of the soil, ECse is 18 dS/m, equivalent to salinity of the soil water extract, ECswe of 32 dS/m (Ayers and Westcot 1989; Lazarova and Bahri 2005). The A. donax Loveday sourced rootstock was exposed to salinities in the soil water extracts, ECswe, of 18-50 dS/m and 15-48 dS/m from February to June in both 2007 and 2008, respectively, data from suction tubes installed at 30, 60 and 90 cm soil depths (Figures 2.1, 2.2 and Table 2.1). This period for the flux of high ECswe in the root zone coincided with the time of maximum growth rate and biomass yields of A. donax (as reported in Chapter 1). Further, the total yield of dry tops of A. donax, Loveday rootstock, of 45.2 t/ha in the first year was similar to that reported for one year regrowth from clearfell for a 30 year old stand of A. donax at Roseworthy Campus, SA of 45.4 t/ha (Williams et al. 2008). These results indicated an extremely high salt tolerance by A. donax, even in the first year of growth under the conditions of this field study at Barmera, SA. Changes in concentrations of chloride ions in soil water extracts were similar to those for ECswe; both indicated high levels of salt in the rootzone at Barmera. There was a marked increase in both these salinity indicators from January to May, for both 2007 and 2008 (Figure 2.2 and Table 2.1) associated with the hot summer temperatures and reduced irrigation inputs at times (eg. 5.8 ML/ha of winery wastewater was applied in this period in 2007).

22

Nitrate levels in soil water should be considered when developing sustainable systems for irrigated crops (Williams et al. 1999). Concentrations of nitrate-N in the soil water extracts from suction tubes at 30 and 60 cm deep in the soil (nitrate mainly from the winery wastewater applied, Figure 2.2 and Table 2.2) were likely to be adequate to high for optimal plant growth at all times in year one (Williams and Maier 1990; Reuter and Robinson 1997; Williams et al. 1999). However, nitrate-N concentrations were unlikely to pose an off site pollution threat as soil water extracts from suction tubes at 90 cm soil depths at Barmera were usually negligible (< 1 mg/L) or low (6 mg/L) during the last 18 months of this project (Table 2.2). a)

Irrigation / Rain (mm)

90

Irrig (mm) Rain (mm) ETo (mm) 30cm EC 60cm EC 90cm EC

40

30 80 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

20

10

Soil Solution EC (dS/m) or ETo (mm)

50

100

0

7 7 7 7 7 7 7 6 6 6 6 6 8/0 /09/0 /10/0 /11/0 /12/0 /01/0 /02/0 /03/0 /04/0 /05/0 /06/0 /07/0 1 1 1 1 1 1 1 1 1 1 1 1/0

b) 20.0

100

17.5 15.0 12.5

80 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

10.0 7.5 5.0

Soil Solution EC (dS/m) or ETo (mm)

Irrigation / Rain (mm)

90

Irrig (mm) Rain (mm) ETo (mm) 30cm EC 60cm EC 90cm EC

2.5 0.0

7 7 7 7 7 7 7 6 6 6 6 6 8/0 /09/0 /10/0 /11/0 /12/0 /01/0 /02/0 /03/0 /04/0 /05/0 /06/0 /07/0 1 1 1 1 1 1 1 1 1 1 1 1/0

Figure 2.1: ECswe and other variables change with time for first year growth of A. donax at Barmera, SA for (a) Loveday, and (b) Henley Beach rootstocks. Soil solution ECswe results are from suction tubes installed at 30, 60 and 90 cm soil depths.

23

350

300

250

200

150

100

50

Nitrate- N Concentration (mg/L)

1/07/2007

0 0

5000

4000

3000

2000

1000

0

0

Sample time (date)

24 1/04/2007 1/05/2007 1/06/2007 1/07/2007

1/04/2007 1/05/2007 1/06/2007 1/07/2007

1/05/2007

1/06/2007

1/07/2007

0

1/04/2007

50

1/03/2007

100

1/03/2007

150

1/03/2007

200

1/02/2007

250

1/02/2007

300

1/02/2007

350

1/01/2007

400

1/01/2007

0

1/12/2006

1000

1/11/2006

2000

1/12/2006

3000

1/11/2006

4000

1/10/2006

5000

1/10/2006

6000

1/01/2007

1/01/2007

1/12/2006

1/11/2006

1/10/2006

1/09/2006

1/08/2006

30cm

1/12/2006

1/07/2007

1/06/2007

1/05/2007

60cm

90cm

1/07/2007

1/06/2007

1/05/2007

1/04/2007

1/03/2007

1/02/2007

Loveday

1/11/2006

1/04/2007

1/03/2007

1/02/2007

60 50 40 30 20 10 0

1/10/2006

1/09/2006

40

1/09/2006

40

1/09/2006

50

1/08/2006

1/01/2007

1/12/2006

60

1/08/2006

50

E.C.(dS/m)

30

Chloride Concentration (mg/L)

1/07/2007

1/06/2007

1/05/2007

1/04/2007

1/03/2007

1/02/2007

1/01/2007

1/12/2006

1/11/2006

Influent Irrigation

1/08/2006

1/07/2007

1/06/2007

1/05/2007

1/04/2007

10

1/11/2006

1/10/2006

90cm

1/06/2007

1/05/2007

1/04/2007

1/03/2007

1/02/2007

10

1/10/2006

1/09/2006

1/08/2006

60cm

1/03/2007

1/02/2007

1/01/2007

1/12/2006

1/11/2006

1/10/2006

20

1/09/2006

E.C.(dS/m)

30cm

1/01/2007

1/12/2006

1/11/2006

1/10/2006

400 1/09/2006

20

1/08/2006

6000

1/08/2006

Chloride Concentration (mg/L) 60

1/09/2006

1/08/2006

Nitrate- N Concentration (mg/L) 60 50 40 30 20 10 0 Henley Beach

Influent Irrigation

30

Sample time (date)

Figure 2.2: Changes in salinity of the influent irrigation, ECw and soil water extracts, ECswe in dS/m, and chloride and nitrate-N concentrations (mg/L) with time for the first year of growth of A. donax at Barmera, SA for Loveday and Henley Beach rootstocks. ECswe results are from suction tubes at 30, 60 and 90 cm soil depths.

Table 2.1: Suction tube soil water ECswe (dS/m), at Barmera, from January 2008 to March a 2009 . Sampling depth of suction tube Sampling Date

30cm

60cm

90cm

Loveday Rootstock 15/01/2008

15.8 (5.1)

18.5 (3.4)

nsp

14/03/2008

23.4 (2.4)

20.7 (3.5)

25.6*

07/04/2008

19.5 (2.3)

19.3 (2.5)

25.2*

01/05/2008

47.8 (31.5)

14.6 (4.2)

17.5*

09/07/2008

13.5 (0.3)

12.0 (3.2)

nsp

30/09/2008

10.7 (2.5)

8.2 (3.1)

4.6*

13/03/2009

7.4 (0.4)

7.7 (1.8)

4.0*

23/04/2009

7.0 (2.3)

8.2 (3.0)

3.1*

Henley Beach Rootstock 15/01/2008

12*

12*

12*

14/03/2008

10*

12.5 (2.1)

10.9 (0.9)

07/04/2008

10*

7.9 (0.6)

7.1 (0.2)

01/05/2008

18.8 (10.9)

6.8 (0.1)

7.1 (0.2)

09/07/2008

16.9 (6.7)

6.0 (0.9)

5.3 (1.3)

30/09/2008

20.6 (14.5)

7.9 (0.8)

7.9 (2.8)

09/01/2009

12.9 (0.1)

8.6 (1.2)

11.4 (2.0)

13/03/2009

6*

6*

5*

23/04/2009

3*

6.1 (2.6)

3.9 (1.4)

a

CSIRO, Land and Water, Analytical Services, Waite Precinct, (standard procedures). nsp = no solution produced * sample produced from 1 replicate only

25

Table 2.2: Suction tube soil water extract nitrate-N (mg/L), at Barmera, from January 2008 to a March 2009 . Sampling Date 15/01/2008 14/03/2008 7/04/2008 1/05/2008 9/07/2008 30/09/2008 13/03/2009

Sampling depth of suction tube 30cm 60cm Loveday Rootstock 121.4 (114.6) 39.5 (38.6) 71.5 (58.4) 93.3 (91.6) 0.3 (0.1) 0.2 (0.1) 7.2 (7.1) 1.9 (1.8) 0.1 (0.02) <0.1 (0.0) 44.4 (43.9) 10.3 (5.3) 12.9 (12.8) 8.9 (8.8)

Henley Beach Rootstock <0.1 4.6* 15/01/2008 1.4* 41.4 (41.29) 14/03/2008 <0.1* 3.4 (2.97) 7/04/2008 41.9 (41.76) 1.3 (1.16) 1/05/2008 0.2 (0.2) 17.6 (17.5) 9/07/2008 <0.1 (0.0) <0.1 (0.0) 30/09/2008 1.9 (1.8) 1.1 (1.00) 9/01/2009 9.1* 0.8* 13/03/2009 14.0 4.5 (1.9) 23/04/2009 a CSIRO, Land and Water, Analytical Services, Waite Precinct, (standard procedures). nsp = no solution produced

90cm nsp nsp 6.1* 0.9* nsp <0.1* <0.1*

2* 0.4 (0.35) <0.1 (0.0) 0.3 (0.18) 0.3 (0.19) <0.1 (0.0) 1.2 (0.8) 5.7* 5.8 (5.7)

Flowers et al. (1986) defined halophytes (salt loving plants) as those plants that can complete their normal annual life cycle under conditions of over 150 mM rootzone salinity (equivalent to 15 dS/m). Our results showed that A. donax can be classified as a halophyte due to its tolerance to salinity of up to 25 dS/m which is equivalent to 250 mM in the soil water solution for prolonged periods (Williams et al. 2009). This was confirmed by Professor Tim Flowers from the University of Sussex, England who assessed our data during a site visit (pers. comm. as cited by Williams et al. 2008). To further assess the salt tolerance of A. donax, the ratios of potassium (K): sodium (Na) in A. donax organs were calculated. The A. donax Loveday rootstock had K:Na ratios for leaf, stem and rhizomes of 62:1, 15:1, and 8:1 respectively, at the final harvest in year 1 (June 2007). These results indicated that the A. donax leaves and stems were excluding Na with a preference for K more than the rhizomes (one possible mechanism of salt tolerance of halophytes, as described by Flowers et al. 1977; 1986). Williams and Biswas (2009) in a related project were the first to define the upper limits of salt tolerance of A. donax for saline irrigation (in a series of greenhouse pot trials). They conducted replicated pot trials using a Loxton loamy sand topsoil and showed that 75% of maximum yield of oven dry top growth of A. donax was recorded at soil saturated paste extract electrical conductivity (ECe) of 8.3 dS/m (Figure 2.3) and 50% of maximum yield at 12 dS/m at both clearfells, cut 1 (Figure 2.3) and cut 2 (irrigated with sodium chloride solutions, the standard world method). Irrigation with Salt Interception Scheme (SIS) water from a Loxton bore (Figure 2.4) produced similar A. donax yield responses to soil salinity (as in Figure 2.3, where pure sodium chloride was used) at both clearfell cuts. SIS Loxton bore water was 49,000 EC units, high in sodium, 8,300 mg/L (90% of total cations) and was diluted with deionised water to achieve the treatment salinity levels (Figure 2.4). Note that the curves in Figures 2.3 and 2.4 are Excel polynomial fits.

26

125

RY (%)

100

75

50

25

0 0

5

10

15

20

25

30

35

ECe (dS/m) Cut 1

Figure 2.3: Relative yield (RY) of dry tops of A. donax in response to the salinity of the saturated- soil extract (ECe). Irrigated with sodium chloride solutions in a pot trial (source: Williams and Biswas, 2009).

The rate of decline of relative yield over the linear portion of the curve in Figure 2.3, from RY, 75% to 25%, was 6.4 % for each unit increase in ECe (per unit dS/m or per 1,000 EC units).

125

RY (%)

100

75

50

25

0 0

5

10

15

20

25

ECe Cut 1

Figure 2.4: Relative yield (RY) of dry tops of A. donax in response to the saturated- soil extract (ECe). Irrigated with SIS water from a Loxton bore in a pot trial (source: Williams and Biswas 2009).

Guidelines for growing Adx with saline wastewaters and for bioremediation For closed systems, where salt inputs equals salt outputs, such as the pot trials conducted by Williams and Biswas (2009) results suggest: (a) A. donax can be grown with an ECe up to 12 dS/m or 12,000 EC units (approximates the upper limits of soil salinity for A. donax in systems (a 50% yield loss is predicted) with over a 20 % leaching fraction under the conditions of the pot trials. (b) Do not exceed soil salinities of 25 dS/m (25,000 EC units) or A. donax plants will be killed, in a few weeks, under the conditions of the above pot trials, with no precipitation for leaching. (c) For sustainable, salt management systems, water and soil salinity must be monitored and managed so that: “salt into the rootzone is less than salt out of the rootzone”. To achieve this, drainage management is critical via the use of a subsurface drainage system and disposal of the concentrated leachate. Estimated costs of

27

such a drainage system are A$5,000/ha (for laser levelling, 65mm diameter pipes spaced from 10 up to 50 metres apart (clay versus sandy soils), approximately 1 metre deep and connected to a sump outlet (drainage for reuse or evaporation or fish farm-Biswas and Williams, 2009). The Serial Biological Concentration (SBC) biosystem, as shown in Figure 2.5, replicates three stages of a land filter system (cell) to produce drainage waters having different salinities at the end of each filtration event due to 33% leaching fraction (after Blackwell et al. 2005). Therefore, by having a sequence of filter cells, as described by Biswas et al. (2002) and Jayawardane et al. (2001), the SBC biosystem allows the growth of salt tolerant crops, such as A. donax and at the same time achieves both a reduction of drainage volumes of wastewaters and maximises the financial returns from the crops produced (Biswas and Williams 2009). The filter cell uses a system of flood irrigation and subsurface agricultural drains to process sewage effluent or other wastewaters by stripping out nutrients, and mitigating pathogens, suspended solids and Biological Oxygen Demand (BOD) using a combination of volatilisation, oxidation, reduction (ie. denitrification), soil adsorption and plant uptake processes. This sequential agricultural process is terminated when the drainage water is too salty to sustain economic crop production. Then the final 3 components of the SBC system in Figure 2.5 can be used. They can consist of production of a range of aquatic species in ponds of varying salinities, and/or salt gradient solar ponds to produce energy and evaporation basins to produce pure salts for industrial use and/or stockpiling for disposal. It is estimated that a well planned SBC system can generate enough electricity through the solar ponds to run all the pumps for irrigation and drainage required for running that SBC biosystem (Biswas and Williams 2009).

Figure 2.5: Schematic representation of possible layout, flows and concentrations of salt in SBC biosystem (modified after Blackwell et al. 2000, from Biswas and Williams 2009).

Preliminary results indicated that A. donax was as effective or more compared to the recommended plant species, such as Phragmites australis (common reed), for the treatment of animal wastewaters in wetlands, as cited in the review by Cronk (1996), especially in terrestrial natural ecosystems (eg. at Barmera), where A. donax can be easily contained (Chapter 3).

28

Plant carbon and nutrient contents and uptake by A. donax (a)

Saline, marginal land, Barmera site The high carbon (C), and moderate nitrogen (N) and potassium (K) contents of A. donax leaf and stem fractions at Barmera (Table 2.3) were similar to those reported for A. donax grown in Europe by Mavrogianopoulos et al. (2002). Critical nutrient ranges have been determined for several irrigated crops, such as wheat (Reuter and Robinson 1997) and potatoes (Williams and Maier 1990). To our knowledge there are no critical nutrient ranges (minimum levels of nutrients for optimal biomass yields as described in Reuter and Robinson 1997) published for A. donax. Thus it is difficult to interpret the impacts of results of the nutrient content of A. donax on response to nutrients and yields. Percent phosphorus (P) and K in dry stems of A. donax at Barmera was 0.03 to 0.1 and 1.4 to 3.1, respectively (Table 2.3) and was similar to such values at Roseworthy (Williams et al. 2008). Furthermore, to examine carbon sequestration below soil level we analysed rhizomes and found they contained 40 to 49% organic carbon on a dry weight basis (Table 2.3). High carbon contents coupled with very high dry matter yields per hectare per year of both tops and rhizomes (Chapter 1) means that A. donax can produce high C yields per hectare per year (Table 2.4). Thus we class A. donax in the premium group of crops for the highest carbon sequestration and biomass yields. Photosynthesis by A. donax during the first year was the likely main mechanism for the large amounts of organic carbon sequestered in plant tops, up to 20.6 t/ha in the dry tops for the Loveday rootstock. The carbon in rhizomes is in dynamic equilibrium from year to year (eg. 12 to 20.4 t/ha/year in the Loveday rootstock, Table2.5) and should qualify for carbon credits when such systems are introduced.

29

Table 2.3: Average carbon and macro-nutrient concentrations (% on a dry matter basis) of A. donax at Barmera for 3 annual clearfell harvests. Standard error of the mean is shown in parentheses.

Treatment

Organic C (%)

N (%)

P (%)

K (%)

Na (%)

Leaf 16/05/2007 20/08/2008 22/04/2009

Loveday 44.3 (0.33) 51.7 (5.11) 47.0 (0.97)

2.5 (0.07) 2.0 (0.03) 2.8 (0.25)

0.10 (0.004) 0.11 (0.010) 0.13 (0.027)

1.8 (0.1) 1.1 (0.2) 2.1 (0.1)

0.03 (0.01) 0.06 (0.01) 0.22 (0.05)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 46.3 (0.88) 47.0 (3.20) 43.0 (0.87)

2.6 (0.03) 3.4 (0.88) 3.4 (0.24)

0.11(0.017) 0.26 (0.050) 0.19 (0.020) Stem

1.9 (0.2) 3.6 (0.6) 3.3 (0.4)

0.13 (0.08) 0.07 (0.02) 0.30 (0.09

16/05/2007 20/08/2008 22/04/2009

Loveday 46.0 (0.58) 51.0 (2.56) 39.8 (364.3)

0.8 (0.06) 0.8 (0.06) 1.6 (0.53)

0.03 (0.007) 0.03 (0.002) 0.04 (0.019)

1.4 (0.2) 1.4 (0.2) 1.6 (0.4)

0.06 (0.03) 0.09 (0.02) 0.14 (0.06)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 47.7 (0.33) 49.3 (1.82) 45.2 (0.71)

0.8 (0.09) 0.7 (0.05) 0.8 (0.17)

0.03 (0.007) 0.03 (0.01) 0.12 (0.017) Rhizome

1.5 (0.2) 1.9(0.3) 3.1 (0.4)

0.12 (0.04) 0.14 (0.01) 0.10 (0.03)

16/05/2007 20/08/2008

Loveday 45.0 (1.0) 49.2 (1.59)

1.3 (0.03) 1.4 (0.08)

0.04 (0.01) 0.03 (0.005)

1.7 (0.1) 1.6 (0.2)

0.21 (0.07) 0.33 (0.05)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 44.0 (1.0) 47.7 (2.39) 40.3 (2.00)

1.4 (0.10) 1.5 (0.12) 1.7 (0.06)

0.05 (0.008) 0.05 (0.01) 0.12 (0.021)

1.8 (0.1) 2.0 (0.2) 1.9 (0.3)

0.19 (0.03) 0.38 (0.03) 0.16 (0.05)

Nutrient uptake of N, P and K in the above ground biomass of A. donax from the Loveday rootstock was 528, 22 and 664 kg/ha, respectively, during the first year of growth (Table 2.5). In comparison, A. donax tops on the Henley Beach rootstock removed 448, 19 and 472 kg/ha of N, P and K, respectively, in the first year after planting (Table 2.4). Concentrations in plant organs and the removal of other nutrients and metals by A. donax biomass during the first year of growth at Barmera are shown in Appendix Tables 2.A.6 to 2.A.7. In general the magnitude of these results is similar to the range observed for a range of grasses and forage crops per unit tonne of dry matter (Reuter and Robinson 1997). However, because of the far higher biomass yields per unit land area produced by A. donax, compared to most other crops (Williams et al. 2008), the total removal of nutrients and metals per hectare is likely to be greater.

30

Table 2.4: Average carbon and macro-nutrient uptake by A. donax at Barmera at 3 annual clearfell harvests. Standard error of the mean is shown in parentheses.

Treatment

Organic C (t/ha)

N (kg/ha)

P (kg/ha) Leaf

K (kg/ha)

Na (kg/ha)

16/05/2007 20/08/2008 22/04/2009

Loveday 4.1 (0.9) 0.4 (0.1) 2.8 (0.3)

239 (58) 15 (6) 161 (6)

9.7 (2.3) 0.8 (0.4) 7.4 (0.9)

163 (32) 7 (2) 126 (11)

2.3 (0.3) 0.5 (0.2) 12.3 (1.8)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 5.3 (2.3) 0.2 (0.1) 1.2 (1.5)

300 (132) 8 (5) 114 (25)

14.0 (7.3) 0.4 (0.3) 6.3 (1.3) Stem

223 (108) 6 (3) 112 (26)

8.2 (4.0) 0.1 (0.1) 10.7 (4.7)

16/05/2007 20/08/2008 22/04/2009

Loveday 16.5(1.4) 1.8 (7.1) 9.1 (1.8)

289 (41) 272(88) 170 (26)

12.4 (3.2) 8.6 (2.6) 8.8 (2.4)

501 (94) 396 (74) 336 (65)

23.7 (10.6) 30.4 (15.2) 29.0 (10.4 )

16/05/2007 20/08/2008 22/04/2009

Henley Beach 8.4 (3.2) 6.2 (1.0) 3.4 (0.3)

148 (55) 90 (8) 98 (9)

5.4 (2.1) 3.1 (0.7) 8.4 (0.6) Tops

250 (81) 228 (23) 229 (13)

15.9 (4.5) 17.5 (2.4) 6.9 (1.8)

16/05/2007 20/08/2008 22/04/2009

Loveday 20.6 (2.9) 18.0 (7.2) 11.9 (2.1)

528(34) 287 (94) 331 (21)

22.1 (1.9) 9.4 (3.0) 16.3 (3.2)

664 (88) 403 (76) 462 (67)

26.1 (6.7) 30.9 (15.5) 41.3 (9.5)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 13.7 (1.9) 6.4 (1.0) 4.9 (0.2)

448 (72) 93 (10) 178 (21)

19.4 (3.9) 3.26 (0.7) 13.2 (1.5) Rhizome

472 (61) 228 (23) 310 (18)

24.0 (3.2) 17.5 (2.4) 11.2 (2.0)

16/05/2007 20/08/2008 22/04/2009

Loveday 12.0 (2.5) 20.4 (4.1) 19.8 (7.3)

352 (66) 561 (77) 598 (157)

9.6 (0.7) 12.5(2.3) 18.1 (2.9)

436 (64) 628 (53) 619 (120)

49 (8) 141 (35) 126 (26)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 7.2 (3.5) 4.8 (0.6) 3.8 (0.1)

232 (101) 144 (12) 146 (7)

8.2 (3.4) 4.5 (0.8) 10.9 (2.0)

281 (119) 192 (22) 168 (26)

27.2 (10.1) 37.3 (3.5) 13.7 (4.9)

31

(b)

Arable land, Roseworthy site The concentrations of organic carbon, N, P and K in the leaf and stem of A. donax were similar at both sites for the sampling times presented in Tables 2.3 and 2.6. Sodium concentrations in leaf and stem organs were higher in A. donax at Barmera compared with Roseworthy due to the saline soil conditions at Barmera (Tables 2.3 and 2.6). Nutrient uptake of N, P and K in the above ground biomass of A. donax from the irrigated, old stand at Roseworthy was 773, 40, and 832 kg/ha, respectively, at the March, 2006 harvest and 657, 45 and 1029 kg/ha, respectively at the final harvest in April, 2009 (Tables 2.6 to 2.8). These results plus the similar data for meso and micro nutrients at these sites (Tables 2.A.6 to 2.A.12) suggest that the saline soil conditions that occurred at Barmera had limited effects on nutrient uptake by A. donax under the conditions of these field experiments. In 2009, the final harvest, rhizomes contained reserves of N, P and K of 907, 52, and 809 kg/ha, respectively in the Roseworthy irrigated old stand (Table 2.8) and the Loveday rhizomes at Barmera contained 598, 18 and 619 kg/ha, respectively (Table 2.4). Thus the rhizomes stored similar amounts of nutrients in terms of t/ha/year, as the plant tops removed at clear fell each year. Furthermore, rhizomes exhibit rhizomatosis, a process whereby a small proportion of rhizomes die each year (usually < 10%) and recycle nutrients to the mother plants (McClure 1993). The reclaimed and recycled waters used to irrigate the giant reed plantings were relatively low in most nutrients, especially N and phosphorus (P) for plant growth (Appendix Table 2.A.5). Electrical conductivity of both wastewaters ranged from 1.2 to 1.5 dS/m and pH ranged from 7.1 to 9.4 at 23rd February and 5th June 2006 sampling times. These figures indicate that salinity was low in the irrigation waters applied to the arable soil at Roseworthy.

32

Table 2.5: Nutrient concentrations for 23 March 2006 harvest for the established planting at Roseworthy. Standard error of the mean is shown in parentheses.

Treatment

Organic C

N

P

K

Na

C1

(%)

(%)

(%)

(%)

(%)

(%) Leaf Non-irrigated

41.8 (1.4)

2.8 (0.03)

0.2 (0.01)

2.5 (0.03)

0.01 (0.003)

0.8 (0.1)

Irrigated

41.3 (2.7)

2.9 (0.1)

0.2 (0.01)

2.0 (0.12)

0.01 (0.001)

0.7 (0.1)

Non-irrigated

41.7 (1.5)

1.5 (0.1)

0.1 (0.01)

2.1 (0.16)

0.003 (0.0005)

0.7 (0.05)

Irrigated

44.0 (1.5)

1.2 (0.1)

0.1 (0.01)

1.5 (0.07)

0.01 (0.004)

0.6 (0.01)

Stem

Table 2.6: Nutrient uptake for 23 March 2006 harvest for the established planting at Roseworthy. Standard error of the mean is shown in parentheses.

Treatment

Organic C

N

P

K

Na

Cl

(kg/ha)

(kg/ha)

(kg/ha)

(kg/ha)

(kg/ha)

(t/ha) Leaf Non-irrigated

1.7 (0.4)

114 (30)

7 (2)

99 (25)

0.5 (0.2)

33 (11)

Irrigated

4.2 (0.1)

298 (9)

15 (1)

208 (2)

0.6 (0.2)

71 (5)

4.8 (1.2)

169 (32)

10 (1)

232 (40)

0.3 (0.04)

86 (23)

18.0 (1.9)

475 (47)

24 (2)

624 (65)

4.0 (1.7)

262 (18)

6.5 (1.6)

282 (62)

17 (4)

331 (66)

0.8 (0.2)

119 (35)

22.2 (1.9)

773 (54)

40 (3)

832 (65)

4.6 (1.5)

333 (13)

Stem Non-irrigated Irrigated Rhizome Non-irrigated Irrigated 1

Tops represents the total of leaf and stem.

33

Table 2.7: Average macro-nutrient concentrations of A. donax at Roseworthy final harvest 2009 (25/06/2009). Standard error of the mean is shown in parentheses.

Treatment Leaf

Organic C

N

P

K

Na

(%)

(%)

(%)

(%)

(%)

2.26 (0.03)

0.12 (0.004)

1.64 (0.12)

0.02 (0.001)

3.03 (0.03)

0.20 (0.01)

2.30 (0.16)

0.01 (0.001)

0.76 (0.06)

0.06 (0.01)

1.40 (0.21)

0.01 (0.01)

1.41 (0.11)

0.09 (0.01)

1.68 (0.23)

0.004 (0.001)

1.72 (0.08)

0.10 (0.01)

1.55 (0.13)

0.10 (0.01)

2.23 (0.16)

0.09 (0.01)

1.04 (0.08)

0.02 (0.004)

Irrigated 48.26 (0.88)

Leaf

Dryland 45.68 (1.66)

Stem

Irrigated 45.02 (0.93)

Stem

Dryland 38.14 (5.26)

Rhizome

Irrigated 43.68 (1.52)

Rhizome

Dryland 43.00 (0.20)

Table 2.8: Average macro-nutrient removals for Roseworthy final harvest 2009 (25/06/2009). Standard error of the mean is shown in parentheses.

Treatment

Organic C (t/ha)

N (kg/ha)

P (kg/ha)

K (kg/ha)

Leaf 1.62 (0.2)

102 (28)

5.7 (1.8)

74 (21)

1.21 (155.3)

81 (12)

5.4 (0.6)

61 (6)

29.28 (6.62)

540 (135)

38.9 (14.8)

945 (298)

1.54 (0.41)

57 (13)

3.6 (0.9)

68 (19)

30.50 (6.0)

657 (169)

45.3 (16.9)

1029 (324)

2.75 (0.4)

138 (13)

9.0 (1.0)

129 (18)

23.00 (4.8)

907 (160)

51.8 (8.3)

809 (124)

10.80 (2.8)

599 (164)

21.3 (1.8)

252 (48)

Leaf Stem Stem Tops Tops Rhizome Rhizome

34

Na (kg/ha) Irrigated 0.8 (0.3) Dryland 0.25 (0.04) Irrigated 7.3 (2.5) Dryland 0.13 (0.02) Irrigated 8.3 (2.2) Dryland 0.38 (0.06) Irrigated 53 (12) Dryland 6.1 (2.6)

Rhizome and root carbon content and nutrient uptake The rhizome of A. donax is a horizontal creeping stem, usually found at or under the surface of the soil. It differs from a root in having scale leaves, or shoots near its tips, and producing roots from its under surface. Rhizomes may also be referred to as rootstocks. The rhizomes and both root fractions of A. donax at Barmera, for both rootstocks had similar carbon contents (38 to 50% C on a dry matter basis) and nutrient concentrations (Tables 2.9 to 2.11). In other crops such as winegrapes (Vitis Vinifera) the feeder or hair roots (less than 2 mm in diameter) usually contain over 3 times the content of most micro nutrients per unit of dry root mass (Williams et al. 2007). This suggests that each root size fraction and rhizomes in A. donax have similar nutrient uptake and storage capacity per unit of dry mass and thus may compensate for each other if parts of the root mass are removed or damaged. Such mechanisms could increase plant survival and regrowth. Table 2.9: Average macro-nutrient concentrations in the rhizomes, string and hair roots for 2 annual harvests of A. donax at Barmera. Standard error of the mean is shown in parentheses.

Treatment

20/08/2008 22/04/2009

Organic C (%) Rhizome Loveday 49.2 (1.6) 4418 (3.3)

20/08/2008 22/04/2009

Henley Beach 47.7 (2.4) 40.3 (2.0)

N (%)

P (%)

K (%)

Na (%)

1.4 (0.08) 1.4 (0.19)

0.03 (0.005) 0.04 (0.003)

1.62 (0.20) 1.39 (0.09)

0.33 (0.05) 0.18 (0.30)

1.5 (0.12) 1.7 (0.06)

0.05 (0.01) 0.12 (0.02)

1.96 (0.24) 1.93 (0.27)

0.38 (0.03) 0.16 (0.05)

20/08/2008 22/04/2009

String Roots (2 to 5 mm diameter) Loveday 34.1 (1.4) 0.92 (0.07) 0.04 (0.003) 41.7 (1.2) 1.72 (0.30) 0.03 (0.01)

1.09 (0.54) 0.84 (0.24)

0.45 (0.06) 0.21 (0.10)

20/08/2008 22/04/2009

Henley Beach 37.7 (5.5) 49.2 (2.8)

0.04 (0.01) 0.03 (0.005)

0.71 (0.04) 0.47 (0.11)

0.15 (0.04) 0.05 (0.01)

20/08/2008 22/04/2009

Hair roots (< 2 mm diameter) Loveday 45.4 (4.7) 0.84 (0.02) 0.03 (0.002) 48* 0.68 (0.35) 0.06 (0.04)

0.71 (0.04) 0.46 (0.01)

0.28 (0.04) 0.19 (0.09)

20/08/2008 22/04/2009

Henley Beach 50.1 (5.2) 47*

0.54 (0.12) 0.19 (0.02)

0.15 (0.02) 0.09 (0.01)

0.80 (0.14) 0.66 (0.11)

0.87 (0.04) 0.98 (0.005)

* One replicate only

35

0.03 (0.002) 0.04 (0.01)

Table 2.10: Average meso-nutrient concentrations of the rhizomes, string and hair roots of A. donax for 2 annual harvests at Barmera. Standard error of the mean is shown in parentheses.

Treatment

20/08/2008 22/04/2009

S (%) Rhizome Loveday 0.30 (0.01) 0.33 (0.03)

Ca (%)

0.07 (0.01) 0.18 (0.05)

0.10 (0.02) 0.11 (0.01)

0.02 (0.002) 0.06 (0.03)

20/08/2008 22/04/2009

Henley Beach 0.33 (0.01) 0.29 (0.00)

0.08(0.01) 0.22 (0.12)

0.07 (0.004) 0.08 (0.01)

0.03 (0.01) 0.10 (0.05)

20/08/2008 22/04/2009

String Roots (2 to 5 mm diameter roots) Loveday 0.41 (0.04) 0.56 (0.09) 0.19 (0.04) 0.28 (0.07) 0.66 (0.06) 0.15 (0.02)

0.48 (0.07) 0.52 (0.12)

20/08/2008 22/04/2009

Henley Beach 0.23 (0.07) 0.14 (0.03)

0.09 (0.01) 0.10 (0.04)

0.33 (0.03) 0.52 (0.06)

20/08/2008 22/04/2009

Hair Roots (<2 mm diameter roots) Loveday 0.23 (0.03) 0.38 (0.07) 0.31 (0.03) 1.10 (0.39)

0.12 (0.02) 0.20 (0.03)

0.03 (0.07) 0.67 (0.16)

20/08/2008 22/04/2009

Henley Beach 0.17 (0.02) 0.24 (0.02)

0.07 (0.01) 0.15 (0.23)

0.23 (0.03) 0.70 (0.14)

0.32 (0.14) 0.50 (0.44)

0.28 (0.08) 0.91 (0.20)

36

Mg (%)

Fe (%)

Table 2.11: Average micro-nutrient concentrations in the rhizomes, string and hair roots of A. donax for 2 annual harvests at Barmera. Standard error of the mean is shown in parentheses.

Treatment /dates Rhizome

Cu

Zn

Mn

B

Mo

mg/kg

mg/kg

mg/kg

mg/kg

mg/kg

20/08/2008

Loveday 2.8 (0.4)

4.4 (1.1)

6.5 (0.8)

2.8 (0.4)

22/04/2009

9.3 (3.9)

17.4 (6.5)

32.7 (11.7)

11.2 (3.4)

Henley Beach 4.0 (1.1) 5.9 (2.5)

4.6 (1.0) 17.0 (3.6)

4.54 (0.9) 15.40 (2.0)

3.90 (0.5) 4.74 (2.8)

< 0.6 < 0.6

String roots (2 to 5 mm diameter) Loveday 20/08/2008 8.1 (0.5) 22/04/2009 8.9 (2.3)

13.2 (0.7) 26.6 (12.0)

28.9 (2.2) 38.6 (3.5)

13.5 (1.7) 16.1 (2.8)

<0.6 <0.6

Henley Beach 12.7 (1.8) 7.57 (2.18)

12.5 (1.0) 18.8 (5.1)

16.5 (2.9) 25.4 (12.4)

11.5 (1.9) 13.7 (2.7)

<0.6 <0.6

8.5 (0.5) 16.9 (1.3)

22.0 (3.3) 43.4 (6.1)

11.3 (1.5) 23.0 (2.5)

<0.6 <0.6

9.7 (1.0) 16.9 (8.1)

13.8 (1.7) 30.5 (14.0)

11.1 (1.6) 14.5 (2.0)

<0.6 <0.6

20/08/2008 22/04/2009

20/08/2008 22/04/2009

Hair roots (< 2 mm diameter) Loveday 20/08/2008 8.2 (0.8) 22/04/2009 21.1 0(10.4)

20/08/2008 22/04/2009

Henley Beach 12.7 (2.5) 16.9 (0.4 )

< 0.6 < 0.6

Changes in soil carbon, and nutrients under A. donax crops There were limited changes in soil organic carbon and total N content, at each depth of sampling during the experiments at Roseworthy and Barmera reported in Tables 2.12 to 2.15. Concentrations of soil nitrate decreased at all soil depths at both the start and end of the A. donax experiments at both sites (Tables 2.12 to 2.15). In general, the pool of soil nitrate was increased by the application of the wastewater and nitrate levels were likely to be adequate to meet normal plant growth requirements (Reuter and Robinson 1997; Williams et al. 1999). However, the effects of chloride inhibition at the saline site at Barmera on nitrate uptake by A. donax are unknown and beyond the scope of this project, but there were no obvious chlorosis symptoms. Wastewater application was associated with increased soil P concentrations by useful but modest amounts at all depths sampled, whereas large increases in K were recorded at all depths sampled after the first year (Tables 2.12 to 2.15). The increased soil K levels recorded associated with application of winery wastewaters need to be monitored in future to assess impacts on soil health and nutrient balance and future Adx growth and yields over several years. Changes in most of the other soil nutrients measured were small (Tables 2.13 to 2.16) and likely of limited biological significance, and thus indicate we have developed potentially sustainable systems for A. donax production using the wastewaters applied under these field conditions.

37

Table 2.12: Comparison of soil organic carbon and nutrients at 29 June 2005 and 28 February 2006 at Roseworthy for the established planting at different soil depths. Standard error of the mean is shown in parentheses. 29 June 2005

Treatment

Organic C (%) Non-irrigated Irrigated Total N (%) Non-irrigated Irrigated Nitrate N (mg/kg) Non-irrigated Irrigated Extractable P (mg/kg) Non-irrigated Irrigated Extractable K (mg/kg) Non-irrigated Irrigated Chloride (mg/kg) Non-irrigated Irrigated

28 February 2006 Soil depth 60-90 cm 0-30 cm 30-60 cm 60-90 cm

0-30 cm

30-60 cm

0.8 (0.08) 1.0 (.22)

0.5 (0.04) 0.6 (0.09)

0.4 (0.02) 0.5 (0.08)

0.9 (0.3) 1.2 (0.2)

0.06 (0.01) 0.08 (0.02)

0.02 (0.01) 0.04 (0.01)

0.03 (0.01) 0.03 (0.01)

16.5 (4.6) 19.0 (6.1)

11.5 (2.1) 13.0 (5.9)

32.5 (1.9) 49.8 (10.3)

0.4 (0.04) 0.6 (0.03)

0.4 (0.05) 0.5 (0.2)

0.08 (0.01) 0.11 (0.02)

0.04 (0.005) 0.05 (0.01)

0.04 (0.01) 0.04 (0.01)

13.0 (3.1) 16.3 (10.8)

45.3 (3.7) 32.0 (4.9)

21.3 (8.8) 7.3 (1.2)

11.5 (0.5) 5.3 (0.9)

7.5 (0.9) 18.5 (3.2)

4.0 (0.4) 5.3 (1.0)

48.0 (11.1) 62.7 (20.0)

21.3 (3.6) 31.0 (12.5)

21.7 (9.0) 7.7 (1.8)

373 (35) 392 (76)

246 (9) 374 (103)

131 (10) 321 (98)

486 (68) 654 (62)

381 (49) 570 (118)

320 (85) 474 (102)

23 (10) 10 (5)

22 (7) 15 (7)

54 (14) 45 (31)

15 (4) 38 (8)

28 (8) 32 (7)

55 (30) 34 (10)

Table 2.13: Soil organic C and macro-nutrients at the final sampling (June 2009) of the A. donax clearfell treatments at the Roseworthy sites.

Treatment Depth Org C Total N (cm)

(%)

(%)

NO3-N

NH4-N

(mg/kg)

(mg/kg)

P K S (Colwell) (Colwell) (mg/kg) (mg/kg) (mg/kg)

Dryland

0-30

1.04

0.07

22

20

40

494

93

Irrigation

0-30

0.91

0.07

9

3

45

285

7.5

38

Table 2.14: Comparison of soil average organic C and macro-nutrients at the start (May 2006), middle (May 2007) and end (June 2009) under A. donax clearfell treatments at the Barmera site. Standard error of the mean is shown in parentheses.

Sampling Time

Depth Org C (cm)

(%)

Total

NO3

NH4

N

N

-N

(%)

P

K

S

(Colwell) (Colwell)

(mg/kg) (mg/kg)

(mg/kg)

(mg/kg)

(mg/kg)

Loveday Rootstock May 2006

23.7

5.0

8.3

399

1176

(8.9)

(2.0)

(0. 7)

(33)

(345)

8.7

3.3

7.3

527

577

(3.8)

(1.9)

(1.5)

(27)

(80)

6.3

1.0

5.3

564

370

(0.88)

(0.0)

(0.88)

(10)

(26)

38.7

1.0

15.7

1847

1375

(11.3)

(0.0)

(3.3)

(481)

(559)

5.0

2.5

7.5

1909

721

(3.0)

(1.5)

(0.5)

(1292)

(200)

0.04 (0.0)

25.0

1.0

8.0

1199

341

(na)

(na)

(2.0)

(485)

(39)

0.75

0.06

54.0

2.0

13.0

1291

1388

30-60

0.32

0.02

11.0

6.0

9.0

1297

1039

60-90

0.25

0.02

5.0

3.0

10.0

2645

331

21.3

8.7

3.7

211

1224

(9.5)

(0.5)

(1.0)

(57)

(380)

6.7

9.0

6.7

243

686

(3.8)

(3.1)

(1.8)

(57)

(219)

4.7

4.3

9.3

317

545

(2.7)

(2.0)

(3.7)

(50)

(100)

25.5

1.0

15.3

2019

995

(11.5)

(0.0)

(0.9)

(312)

(468)

14.7

3.3

26.3

1305

389

(6.2)

(1.9)

(16.3)

(128)

(156)

0-30

0.78 (0.33)

0.06 (0.02)

0.27 (0.04)

0.03 (0.0)

0.22 (0.01)

0.03 (0.0)

0.83 (0.30)

0.07 (0.04)

0.33 (0.05)

0.04 (0.0)

0.29 (0.01)

0-30

30-60 60-90 May 2007

0-30 30-60 60-90

June 2009

a

Henley Beach Rootstock May 2006

0-30

0.58 (0.32)

0.05 (0.03)

0.20 (0.03)

0.02 (0.0)

0.15 (0.02)

0.01 (0.01)

0.58 (0.21)

0.06 (0.02)

0.25 (0.03)

0.03 (0.0)

0.23 (0.0)

0.02 (0.0)

11.5

7.5

13.0

1086

385

(3.5)

(6.5)

(4.0)

(921)

(183)

0-30

0.67

0.03

30.0

9.0

23.0

896

610

30-60

0.24

0.02

5.0

8.0

31.0

848

193

8.0

31.0

1250

243

30-60 60-90 May 2007

0-30 30-60 60-90

June 2009a

a

60-90 0.21 0.02 3.0 Samples bulked over replicates. na = not available

39

Table 2.15. Soil average organic C and macro-nutrients at the start (May 2006), middle (May 2007) and end for the control area of the Barmera trial. Standard error of the mean is shown in parentheses.

Treatment

Depth (cm)

Org C (%)

Total N

NO3

NH4

P

K

S

-N

-N

(Colwell)

(Colwell)

(%)

(mg/kg)

(mg/kg)

(mg/kg)

(mg/kg)

(mg/kg)

Control May 2006

0.79 (0.15)

0.07 (0.01)

16.7 (6.9)

9.7

6.33

180

(3.8)

(0.3)

(7)

0.23 (0.01)

0.02

5.3

3.0

85

(1.9)

11.3 (3.7)

(0.002)

(0.01)

(26)

0.18 (0.05)

0.01 (0.001)

3.3

8.3

3.7

80

(0.7)

(1.5)

(0.3)

(11)

696 (267)

0-30

0.52

0.06

12.0

7.0

4.0

180

1487

30-60

0.18

0.02

5.0

12.0

2.0

81

657.

60-90

0.13

0.03

4.0

14.0

2.0

69

313

0-30

0.91

0.03

19.0

12.0

5.0

205

1697

30-60

0.25

0.02

5.0

15.0

2.0

92

754

60-90

0.15

0.02

4.0

16.0

2.0

85

546

0-30 30-60 60-90

May 2007

June 2009

a

a

a

1557 (325) 721 (252)

Samples bulked over replicates, therefore standard error does not apply. na = not available

Conclusions We have shown that A. donax is a highly salt tolerant plant (halophyte). Under the saline field conditions at Barmera, the Loveday rootstock of A. donax survived and produced very high yields (up to 45.2 t/ha of dry top growth per year) on marginal land using low quality, saline wastewater without pesticides. Salinity, in terms of the Electrical Conductivity of the soil water extracts (ECswe) was over 25 dS/m (approximately 40% of open ocean) at Barmera for several months during summer for the Loveday rootstock. The ECswe declined to approximately 10 dS/m in winter with leaching by rainfall. In a closed system, where salt inputs are equal or less than salt outputs, pot trial results showed that there was a 50% biomass yield penalty at a constant 12 dS/m of the soil saturated paste extract ECe. The ECe of 12 dS/m is equivalent to approximately an ECswe of 24 dS/m (Maas, 1992). Ongoing drought in many regions has renewed the interest in alternate uses of saline wastewater rather than disposal to evaporation basins. The Serial Biological Concentration (SBC) system is an integrated sustainable biosystem, which offers communities the potential to generate returns from wastewater flows by growing salt tolerant crops such as Adx rather than discharging wastewaters to evaporation basins or the ocean. A. donax removed large amounts of nutrients. The tops of the Loveday rootstock removed N, P, and K at rates of 528, 22 and 664 kg/ha, respectively (much from applied wastewaters) in the first year of growth at Barmera. Therefore, A. donax acted as an interceptor crop for water with high nutrient loads could be effective in to prevent their entry into riparian and groundwater systems. However, long term field trials in Europe reported that A. donax energy crops can also produce high biomass yields under low nutrient input regimes (Christou et al. 2001; Lewandowski et al. 2003; Angellini et

40

al. 2005). Furthermore, the Loveday rhizomes at Barmera contained 352, 10 and 436 kg/ha of N, P and K, respectively, at the end of the first year of growth. On the other hand, A. donax rhizomes exhibit rhizomatosis, a process whereby a small proportion of rhizomes die each year (usually less than 10%) and recycle nutrients to the soil and mother plants. If A. donax is grown with high N wastewater, nitrate concentrations in the soil water solution should also be monitored and managed (Williams et al. 2007). Further research is needed to define the minimum nutrient and irrigation requirements of A. donax for target biomass yields for a range of different environments. Our work has shown the salt tolerance of A. donax and its potential to be produced under conditions of high salt and nutrient load wastewaters (eg. sewage or winery wastewaters) and to produce high biomass in natural terrestrial ecosystems where it can easily be contained (Chapter 3).

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Chapter 3: Weed risk management guidelines for Arundo donax plantations in Australia John Virtue1*, Tim Reynolds1, Jenna Malone2, Chris Preston2, Chris Williams3 and Robin Coles4 1 Department of Water Land & Biodiversity Conservation, GPO Box 2834 Adelaide SA 5001 2 School of Agriculture Food & Wine, The University of Adelaide, PMB 1 Glen Osmond SA 5064 3 South Australian Research and Development Institute, GPO Box 397, Adelaide SA 5001 4 Rural Solutions SA, Lenswood Research Centre, Swamp Rd Lenswood SA 5240 * Corresponding author: [email protected]

Introduction A. donax (giant reed, Poaceae) is a robust, perennial, reed-like grass 3-9 metres tall, growing in manystemmed, cane-like clumps, spreading from horizontal rootstocks below the soil, and often forming large colonies many metres across. The stems or culms are hollow with bamboo-like nodes, with leaves arranged alternately on original stems and opposite on young suckers. Stems have a plumelike, terminal inflorescence (DiTomaso and Healy 2007). A. donax is a controversial plant, native to Asia and southern Europe, it has been introduced around the world as an erosion control plant to stabilise channel banks, as a windbreak, as an ornamental and as a source of reeds for musical instruments. It has since become invasive, most prominently in riparian corridors in California, and is the subject of many, broadscale control programs. The Invasive Species Specialist Group of the IUCN Species Survival Commission has nominated the giant reed (A. donax) as one of the 100 of the World’s Worst Invasive Alien Species (Lowe et al. 2000). In Australia, A. donax is not currently considered to be a major weed on a national or state scale. It has been present since the mid 1800s and has been widely planted across the country. However, given its weed impacts overseas there has been concern about its invasive potential, particularly as it has shown considerable potential as a biomass crop (eg. Low and Booth 2007). The risk of invasion of biofuel crops into natural ecosystems, with subsequent effects on biodiversity, is a growing international concern. Draft International Union for the Conservation of Nature guidelines (IUCN 2009) recommends that risk assessment, benefit:cost analysis, selection of native or low risk species, risk management of any escapes and certification/accreditation\processes be considered in the development of biofuel crops. The management of weed risk issues for A. donax has become increasingly important because recent research has quantified significant benefits of A. donax to human kind. These include: classing A. donax in the premium crop group for the highest dry matter yield per hectare per year when grown on marginal lands for livestock fodder or industrial uses (Williams et al. 2008a), it is salt tolerant (Williams et al 2008b) and produces high quality cellulosic feedstock with potential for profitable ethanol or pulp/paper production (Williams et al. 2008 a, b). This chapter analyses the weed risk of A. donax, with a particular focus on seeking any evidence of sexual reproduction occurring within Australia. The outcome of the analysis indicates that A. donax could be safely grown in non-riparian or othe flood prones zones with strict management guidelines.

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A. Analysis of weed risk and control feasibility for A. donax Introduction Weed risk management is the application of models based on technical criteria to determine the potential threat of a plant species to naturalise, spread and subsequently cause significant negative economic, environmental and/or social impacts, warranting control measures. The post-border application of weed risk management in Australia, which aims to prioritise weed species threats, has been standardised through the collaborative development of a national protocol (anonymous 2006), based on the national risk management standard (AS/NZS 4360:2004). The South Australian Weed Management System, SAWRMS, (Virtue 2010) aligns with the national WRM protocol. It is based upon a system originally proposed to determine Australia’s Weeds of National Significance and has been adapted for other jurisdictions including Northern Territory and New South Wales. In the SAWRMS a score for Comparative Weed Risk (CWR) is generated from multiplying separate scores (each ranging between 0 and 10) for the three criteria of ‘Invasiveness’, ‘Impacts’ and ‘Potential Distribution’. Hence CWR has a minimum of 0 and a maximum of 1000. Invasiveness considers the establishment, reproductive and dispersal abilities of weed species, providing an indicator for rate of spread. Impacts consider the types and magnitude of economic, environmental and social effects that the weeds can have. Potential distribution considers the geographic area that could be invaded by the weed. The SAWRMS also generates a score for ‘Feasibility of Containment’ (FoC), by multiplying separate scores (again, each ranging between 0 and 10) for the three criteria of ‘Control Costs’, ‘Current Distribution’ and ‘Persistence’. Control costs consider the weed management costs of detection, onground control and enforcement/education needs. Current distribution considers how widespread the weed is at present. Persistence refers to the expected duration of a control program. Scores for each of the six criteria are generated from a series of multiple-choice questions (eg. high/medium/low), with definitions to aid in consistency of assessments. Weeds are assessed within land uses (eg. crop/pasture rotation, native vegetation, forestry, urban) as this avoids contention over the relative values of land uses in a region of interest. CWR and FoC scores have been categorised into five levels (ranging from negligible to very high), which enables weed species to be placed on a simple prioritisation matrix for each land use. The matrix indicates the most appropriate management action (eg. prevention, eradication, containment, integrated weed management).

Methods A. donax was assessed using the SAWRMS for its potential to invade two land uses; riparian and terrestrial natural ecosystems. Riparian includes river, creek and lake systems, including standing/flowing water, banks and adjacent floodplains. Terrestrial natural ecosystems relate to native vegetation remnants in the landscape that are distant from water bodies and not subject to flood events. For both land uses it was assumed that, on average at the regional scale, there were no routine weed management practices undertaken. Information to answer questions within the SAWRMS were obtained from a review of literature, and field and laboratory data generated for this project, weed risk analyses undertaken by other jurisdictions and personal observations of stands of naturalised A. donax. Data on the national distribution of the species was obtained from Australia’s Virtual Herbarium (CHAH 2009). Modelling potential distribution requires input location data with good geographic precision. Simply inputting whole country climate datasets into a model ignores potentially large within-country variation in climate (often linked to altitude). Hence, whilst the native range of A. donax extends across the Meditteranean, Middle East, Central Asia, Indian subcontinent and South-East Asia, not all

43

countries could be included due to data gaps in the scientific literature sourced. Point and locality data for the global native and naturalised range of A. donax were obtained for: • • • • • •

USA (Missouri Botanical Garden 2008, USDA-NCRS 2009); Central and South America (Missouri Botanical Garden 2008); Meditteranean countries (GBIF-Participants, GRIN 2008); South Africa (AGIS 2007); Central Asia (Tsvelev and Fedorov 1984, Khuzhaev 2004), India (Krishnan et al. 2000, Sharma et al. 2005, Shah and Menon 1980, Prakash et al. 1978, Deb and Dutta 1971, Talapatra 1950, Ghosal et al. 1971, Dinerstein 1979) and China (FOC 2006); and New Zealand (Landcare-Research 2008).

These locations were selected in Climatch, a global climate-matching software program (Crombie et al. 2008), and a ‘Closest standard score’ algorithm was used for temperature parameters only. Rainfall parameters were excluded as A. donax is recorded as a predominantly riparian species in its native and introduced regions (FOC 2006, Sharma et al. 2005, DiTomaso and Healy 2007, Henderson 2001). Weather stations >1000m altitude were excluded from the analysis.

Results Comparative weed risk Figure 3.2 shows the scoring for invasiveness, impacts and potential distribution in the two land uses, with a combined score for CWR. Information to inform the scoring is presented below. The majority of the references originate from the USA, where A. donax invasion has been extensively studied.

Invasiveness Establishment • • •

• • •

•

•

Riparian zones are particularly vulnerable to invasion by exotic plants such as A. donax due to recurrent disturbance caused by flooding, transport of propagules in water, and availability of water for growth (Hood and Naiman 2000). It is well adapted to the high disturbance dynamics of riparian systems (Bell 1997). Spread and persistence of giant reed arises from its vigorous production of lateral rhizomes as well as establishment from layering of stems (Boland 2006). Layering is growth from buds in leaf axils when stems come into contact with the ground, whether still attached or dislodged from parent clumps. In Australia and the USA A. donax is not known to reproduce by seed (see reproduction section below), so establishment is wholly vegetative. Tolerates a wide range of soil types, including infertile stream-banks, but responds dramatically to nutrient enrichment (Dudley and ISSG 2006). A. donax establishment in riparian habitats is promoted by both vegetative reproduction and favorable abiotic environmental factors and relatively unaffected by the composition of the native community. There is a positive response of A. donax to disturbance (bare ground) and high resource availability (soil moisture) (Quinn and Holt 2008). A. donax is more likely to establish in field conditions that provide bare ground and ample soil moisture. These factors were positively related to survival and height when considered across all sites and years, and individually in at least two of the sites. These conditions would be expected in the period following seasonal flooding in a riparian area. (Quinn and Holt 2008). A. donax rhizomes can sprout under a range of moisture regimes from dry to wet, with cool temperatures increasing success in wet conditions (Boose and Holt 1999).

44

•

Within a river system the distribution of establishment does not appear to be random. The highest concentration of colonies occurs closest to the river. Frequency and magnitude of the river flow is most likely the major contributing factor influencing this pattern of distribution (Rieger and Kreager 1989).

Tolerance to routine weed management measures •

The standard assumption with the SAWRMS is that there is no broadscale, routine weed management in natural ecosystems. Hence the default is the maximum score.

Reproduction • •

•

• • • • •

A. donax does not produce viable seeds in most areas where it is apparently well-adapted, although plants have been grown in scattered locations from seed collected in Asia (Perdue 1958). Johnson et al. (2006) detected five potentially viable ovules (as determined by tetrazolium staining) out of ~36,666 florets from 244 plumes collected over 31 sites in North America. This did not confirm viable seed production but did indicate it may be an extremely rare event, with little ecological significance in the reproduction of A. donax. Johnson et al. (2006) also observed pollen production to be low and suggested that male sterility could be a factor limiting fertilisation. Bhanwra (1988) found that seed set was poor in India due to the failure of meiosis in the majority of ovules.It is commonly claimed that lack of seed set is due to polyploidy, but no studies have been located to substantiate this. A. donax has a chromosome number of 2n = 110 (El Bassam 2010). Genetic analyses of A. donax plant samples from SA and other states has found a very high level of genetic similarity, indicative of clonal spread as the only reproductive mechanism in Australia (see section 2 of this report). Four hundred seeds from each of five locations in SA were found to not have viable embryos of A. donax (Williams et al. 2008a). Genetic studies in the USA have shown clonal reproduction only (Khudamrongsawat et al. 2004, Ahmad et al. 2008, Rana and Holt 2004). Primary mode of reproduction reported over majority of world distribution is vegetative; however some populations in Asia have been reported to produce viable seed (DiTomaso and Healy 2007). New ramets arise from nodes along stems or rhizomes. Although stems may survive for several years, the rhizome is the primary perennating organ and the source of most new ramets in either intact stands or flood-deposited litter mats. New plants establish much more frequently from rhizomes than stems. Much lower likelihood of establishment from detached stem material in the field than from rhizomes, especially if stems are kept away from constantly moist soil. (Decruyenaere and Holt 2000).

Dispersal • •

• •

In California, dispersal is usually by floodwater (Decruyenaere and Holt 2000). Dense monocultures of A. donax in streambeds, riverbanks and floodplains can arise from dislodged vegetative material spread by water. However, in other respects, it is limited in its dispersal ability. Unlike some invasive bamboos, A. donax rhizomes have a limited spreading growth habit, with plants forming well-defined clumps (Lewandowski et al. 2003). No fertile seed production (see Reproduction section, above). Boland (2006) presents a general view of A. donax invasion whereby fragmentation is the means by which A. donax invades a new site in the flood zone, expansion via rhizomes maintains an A. donax clump, and layering is the means by which A. donax spreads quickly and episodically within the flood zone. Outside the flood zone, A. donax expands slowly via rhizomes only and no new recruits arrive from either fragmentation or layering.

45

• • • •

•

•

Has historically been widely planted in rural settlements and cities in Australia, but rarely sold in general nurseries today. Mechanical damage caused by humans can lead to long distance transport in water to new sites (Dudley 2000). Deliberately grown for fencing, thatch, framing, musical instruments and woodwind reeds (Dudley and ISSG 2006). Rhizome and stem fragments may occasionally result from the impact of large, intense floods in the Southern California riparian ecosystems (Jesse 1996). The rhizomes of an A. donax stand can be undercut by the eroding action of fast-moving floodwaters, then stems and/or rhizome fragments can break off (Wijte et al. 2005). A two-year field study in the Tijuana River Valley, California, found that expansion of A. donax clumps via rhizomes was slow (0.29 m2 yr-1), and new recruits from fragments were rare (4.7 ha-1 yr-1). However, layering was common in the flood zone. When viewed as clump expansion, layering was 7.4 times faster than the annual expansion via rhizomes. When viewed as reproduction (i.e. new plants detached from parent plant), layering produced 25 times more new recruits than fragments. Layering was therefore an important means by which A. donax was spreading within the flood zone. A new general view of A. donax invasion is presented illustrating that fragmentation is the means by which A. donax invades a new site in the flood zone, expansion via rhizomes maintains an A. donax clump, and layering is the means by which A. donax spreads quickly and episodically within the flood zone. Outside the flood zone, A. donax expands slowly via rhizomes only and no new recruits arrive from either fragmentation or layering. (Boland 2006) Can withstand high wind loads without mechanical damage (Speck 2003).

Impacts Figure 3.2 shows the scoring for impacts in the two land uses. Information to inform the scoring is presented below. Density • • • •

Once established, A. donax tends to form large, continuous, clonal root masses, sometimes covering several acres, usually at the expense of native riparian vegetation, which can not compete (Bell 1997). A. donax becomes a dominant component of the flora, and was estimated to comprise 68% of the riparian vegetation in the Santa Ana River in California (Douthit 1994). Plants near the stream produced taller stems with more leaves per stem than those more distant from the stream (Spencer et al. 2005). Increase in density would be extremely slow in terrestrial natural ecosystems, due to the absence of effective natural dispersal of vegetative fragments by floodwaters. However, some spread by layering could occur for sites/regions with or during periods of high surface soil moisture.

Competitiveness • • • •

A. donax displaces native plants and associated wildlife species because of the massive stands it forms (Bell 1994, Gaffney and Cushman1998). A. donax is a high water user and causes substantial light reduction in its understorey, hence competing strongly with neighbouring native plants (Dudley 2000, Mack 2008). Within its introduced range, A. donax is an aggressive competitor. A. donax displaces native riparian vegetation and provides poor habitat for terrestrial insects and wildlife (Dudley and ISSG 2006). A. donax tolerates a wide range of environmental or human related stresses, including extreme temperature, drought, floods, damage, diseases, fire and mechanical disturbance (Bautista 1994).

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• •

• •

In the USA, dense, homogenous stands of A. donax create zones essentially devoid of wildlife and its presence is viewed as being potentially disastrous for the overall habitat quality of the riparian system (Rieger and Kreager 1989). In a USA study, the total number of organisms, total biomass and taxonomic richness of aerial invertebrates associated with native vegetation was approximately twice that associated with Arundo-dominated vegetation, while mixed vegetation supported intermediate arthropod levels. A. donax invasion changes the vegetation structure of riparian zones and in turn, may increasingly jeopardize its habitat value for birds and other wildlife whose diets are largely composed of insects found in native riparian vegetation (Herrera and Dudley 2003). In South Africa, A. donax dominated communities had higher species richness, but reduced indigenous species diversity and a greater number of alien species co-occurring with it than did communities dominated by indigenous species (Guthrie 2007). Like other ruderal species, growth rates in A. donax are extremely rapid. This may allow A. donax to pre-empt and monopolize space and nutrients on newly exposed floodbanks to the detriment of small-statured ruderals (Quinn et al. 2007).

Movement • • •

A. donax is an archetypal phalanx-forming species, in which the tightly packed culms spread laterally and form an impenetrable mass, which can restrict the physical movement of people, animals and vehicles (Mack 2008). A. donax slows water flow (Bell 1997). Fastmoving floodwaters have caused the buildup and fragmentation of A. donax structures in drainage pipes and behind bridges and flood control structures (Bell 1994).

Health risks • •

A. donax has been linked to incidents of contact dermatitis when used as reeds for woodwind instruments (McFadden et al. 1992). However, Professor L. Marton (Univ. South Carolina, USA, pers. comm.) reported that A. donax produced no detrimental effects on chicken growth when it was used as bedding for day old chickens (results of contract trials).

Ecosystem health • • •

• •

A. donax is suspected of altering hydrological regimes and reducing groundwater availability by transpiring large amounts of water from semi-arid aquifers (Dudley 2009). Large stands can significantly increase water loss from underground aquifers in semi arid regions due to a high evapo-transpiration rate, which is estimated at roughly 3 times greater than that of the native riparian vegetation (DiTomaso and Healy 2007). A. donax has a high evaporation rate, is drought tolerant and can be highly flammable during drier times of the year. In California it has been reported as a driving factor in changing wetlands from that of flood disturbed to that of fire disturbed, having a significant impact on the native species (Tracy and DeLoach 1998). Dense growth presents fire hazards, often near urbanised areas, more than doubling the available fuel for wildfires and promoting post-fire regeneration of even greater quantities of giant reed (Scott 1993, Gaffney and Cushman 1998). A. donax restricts water flow, which can contribute to mosquito habitat (Bell 1997).

47

Potential distribution The predicted distribution in Australia (Figure 1.1), based on temperature only, may be an overestimate as it has not been refined according to the presence of creeks, rivers and other permanent freshwater/estuarine bodies and flood prone areas. However, it shows that A. donax could grow across Australia, given access to a moist substrate. This reflects its current world distribution, which spans tropical, arid, mediterranean and temperate climates. Including rainfall parameters (data not shown) did not substantially decrease its potential range in riparian areas across the Australian continent. Essentially all climate zones in Australia are suitable for A. donax, provided there is a sufficient supply of soil moisture. However, potential distribution within terrestrial (non-riparian) areas would be very low, as natural spread is highly unlikely without flooding events to move reproductive vegetative fragments. Further information to inform the scoring is presented below. •

•

In field trials, 5–6% volumetric water content in sandy soil was the critical soil moisture level below which development ceased and rhizomes were unable to sprout. This may be a biologically reasonable estimate of a base threshold in sandy-loam soil typical of the stream banks infested by A. donax. (Graziani and Steinmaus 2009) Neither root nor shoot production from A. donax rhizome fragments were affected by temperatures ranging from 5 to 35oC. Emergence time and shoot height did not differ in shade treatments ranging from approximately 18% of full sun to 100% full sun (Quinn et al. 2007).

Figure 3.1: Predicted distribution of A. donax in Australia (based on temperature only and not refined to areas with riparian ecosystems only). Higher scores have greater matches.

48

49

50

Figure 3.2: Scoring for Comparative Weed Risk in the riparian and terrestrial land uses.

51

Feasibility of containment Figure 3.4 shows the scoring for control costs, current distribution and persistence in the two land uses, with a combined score for FoC. Information to inform the scoring is presented below.

Control costs Detectability • • •

A. donax is a very tall grass, with established stands reaching heights of 2-6 m (Jessop et al. 2006). Young, individual plants would reach this height before vegetative spread via fragmentation is likely. In southern Australia, A. donax may be confused with Phragmites australis (which has narrower stems) or bamboos (which have clusters of shorter leaves on side branches along the main stem). A. donax is perennial and its stems and leaves are present year round.

Accessibility •

Riparian zones can be difficult to access due to water bodies, steep terrain, boggy ground, and dense vegetation. In contrast, A. donax in terrestrial areas is likely to have arisen from plantings and would be readily accessible (eg. roadsides).

Control techniques • • • •

Queensland research recommended cut stump application of 167 mL Glyphosate CT/L water or foliar spray of 20 mL Glyphosate 360/L water in autumn (Armstrong and Breadon 2005). Carbohydrates move from leaves to belowground structures in late summer-early autumn in California, prior to natural leaf senescence. This indicates that phloem-mobile herbicides such as glyphosate would be most effective applied at this time (Decruyenaere and Holt 2000). 3% or 5% foliar applications with glyphosate (with additional surfactant) were the most effective and consistent treatments for killing giant reed with a single late-season application (Spencer et al. 2008). Because of its reduced efficacy, and due to the labour required, cut stump application is rarely cheaper than foliar spraying of A. donax, except on very small, isolated patches or individual plants (Bell 1997).

Landholder cooperation •

Due to resource constraints, weed management in natural ecosystems is generally undertaken on a small scale at high biodiversity sites. A. donax is not currently declared across Australia (with the exception of the Sydney region), so land holders are not legally obliged to undertake control. Within riparian areas there can be a range of government and private landholders with responsibility for particular land parcels. The cut and paste treatment with glyphosate herbicide is a quite simple weed control technique, with the main difficulties in it’s use being equipment to cut thick stems and accessibility to sites. There would be resistance from landholders to control A. donax where it is performing a physical function such as soil stabilisation, windbreak or privacy screening.

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Current distribution Figure 3.3 shows herbarium records for A. donax lodged within Australian herbaria, as at August 2009. This does not necessarily indicate naturalised populations, as some may be historic plantings. Distribution is also likely to be much more frequent across Australia, as naturalised stands in riparian areas (eg. in rivers of the lower Hunter Valley in NSW – www.lhccrems.nsw.gov.au) and as plantings. A. donax has been in cultivation in Australia since at least 1841 (Jessop et al. 2006) and can commonly be found as small amenity plantings near old urban and rural dwellings.

Figure 3.3: Australian herbaria records for A. donax (Australia’s Virtual Herbarium www.anbg.gov.au/avh 20/08/09).

Persistence Control effectiveness • •

There was no regrowth from rhizomes in the following spring-summer after an autumn foliar application with 3% or 5% glyphosate (Spencer et al. 2008). 100% kill rates would be unlikely in dense stands due to the likelihood of missing some stems when applying foliar herbicide.

Time to reproduction • • •

No viable seed production known to occur in Australia (see above and section 2). Stem cuttings at different developmental stages revealed very low establishment from unlignified stem segments in their first growing season (Decruyenaere and Holt 2000). Plants newly established from rhizome fragments likely to take at least a year before fragmentation could re-occur in the event of torrential flooding.

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Longevity of propagules • •

Rhizomes can remain viable for long periods of time after isolation from the parent plant, even after up to 60% of fresh weight has been lost (Jesse 1996). However, stems are not nearly as hardy (Decruyenaere and Holt 2000). Stem viability is relatively ephemeral (Boose and Holt 1999, Jesse 1996).

Reinvasion • •

Natural dispersal is essentially by torrential flooding events dislodging stems and rhizomes. Occasionally grown as, largely historic, amenity plantings. But now rarely offered for sale by Australian nurseries. A variegated form is grown as a garden ornamental.

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55

F igure 3.4: S c oring for F eas ibility of C ontainment in the riparian and terres trial land us es .

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Weed Risk Management Action Matrix Comparing CWR and FoC scores for the two land uses (Figure 3.5) allocates the management action of “Destroy Infestations” for A. donax in riparian natural ecosystems and “Monitor” for A. donax in terrestrial natural ecosystems.

FEASIBILITY OF CONTAINMENT Negligible >113

Low >56

Medium >31

High >14

Very High <14

Negligible <13

LIMITED ACTION

LIMITED ACTION

LIMITED ACTION

LIMITED ACTION

Low <39

LIMITED ACTION

LIMITED ACTION

LIMITED ACTION

MONITOR

MONITOR

Medium <101

MANAGE SITES

MANAGE SITES

MANAGE SITES

PROTECT SITES

CONTAIN SPREAD

High <192

MANAGE WEED

MANAGE WEED

PROTECT SITES

CONTAIN SPREAD

DESTROY INFESTATIONS

Very High >192

MANAGE WEED

PROTECT SITES & MANAGE WEED

CONTAIN SPREAD

DESTROY INFESTATIONS

A. donax

MONITOR

terrestrial

ALERT

WEED RISK

A. donax

ERADICATE

riparian

Figure 3.5: Weed risk management action matrix and locations of the two land uses assessed for A. donax.

Discussion A. donax was assessed as a very high weed risk to riparian natural ecosystems at a national scale. Given its assessed feasibility of containment, the suggested management action from the SAWRMS was “Destroy infestations”. This action aims to significantly reduce the extent of the weed species in the management area, via: • • • • •

Detailed surveillance and mapping to locate all infestations Destruction of all infestations, aiming for local eradication at feasible sites Prevention of entry to management area and movement and sale within Must not grow Monitor progress towards reduction.

In this regard it is clear that A. donax is not suitable to be grown in riparian areas, nor be allowed to spread to such areas. Noxious weed authorities should also consider control programs to remove any existing stands of A. donax in such areas. Conversely, A. donax was assessed as a negligible weed risk to terrestrial natural ecosystems on a national scale. Its limited current distribution influenced its feasibility of containment assessment as very high, with “Monitor” the suggested management action. This action aims to detect any

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significant changes in the species’ weed risk through ongoing monitoring of the spread of the species and regular review of any perceived changes in weediness. In this regard there are no significant concerns with growing A. donax in terrestrial areas, provided ongoing protocols are in place to prevent any spread to riparian areas.

B. Genotyping A. donax in Australia Introduction An aim of this work was to determine the genetic variation within A. donax in Australia. If variation was low, this would support A. donax only having vegetative reproduction in Australia and posing a lower risk of spread. To do this, Amplified Fragment Length Polymorphism (AFLP) analysis of 167 A. donax samples from South Australia, five from interstate and five from the USA has been undertaken. AFLP analysis was used to identify genetic variations by looking for differences in the lengths of randomly amplified DNA fragments between individuals. Differences indicates sequence differences in the DNA and hence variation among individuals.

Samples Sampling focused on South Australia, with 167 samples taken (Figure 3.9). Interstate samples were also collected (Figure 3.5) as follows: 1 from Kununurra, WA; 1 from the Brisbane Botanical Gardens; 1 from Townsville and 2 from Sydney. The results for 10 samples were of poor quality and are not included in the analysis: (T19, T48, BG4, 252, 256, 262, 285, CW10, CW20, Townsville). Five A. donax samples from the US, kindly provided by Dr. Marie Jasieniuk, UC Davis, were also included for comparison. These were from California, Colorado, Nevada and Texas. In addition, 2 Phragmites australis samples (1 from South Australia and 1 from Victoria) were included as outgroups. AF L P Method DNA was extracted from around 2 cm2 of the freshest/youngest leaf material using standard methods. The DNA was digested with Mse and Pst restriction enzymes. In this reaction the DNA is cut into fragments at specific sites and then adaptors (tags on the ends used for amplifying from) are ligated to the ends of the fragments. PCR reactions were conducted with primers corresponding to the restriction site +1 base (Mse+C and Pst+A) overhang. A second round of PCR was conducted with primers corresponding to the restriction site + 3 bases for more selection. In this reaction, the Mse primer incorporated a fluorescent tag so that the amplified fragments can be measured. The primers used were Pst+ACG and either Mse+CAA+Vic (Green) or Mse+CAT+Fam (blue). This method produces ‘peak’ data as shown in Figure 3.6 below. Each ‘peak’ was called a genetic marker and the presence or absence of markers in individuals was compared. In total, 340 markers were compared in this study

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Figure 3.6: Example of data generated from AFLP analysis.

Results When the genetic fingerprints of all samples were compared it was found that there were groups of identical individuals. Not all samples from Australia were identical; however, most showed less than 1% genetic diversity (differences in 3 markers out of 340). The identical samples were grouped together (Figure 3.1) and one representative from each group used to produce a second, clearer dendrogram (Figure 3.2). Most of the South Australian samples, the sample from Brisbane and the sample from Kununurra grouped into a single clade with low genetic divergence. A second clade consisted of both samples from Sydney and 4 samples from South Australia. Again, these samples were very similar to each other, but were quite different to the common genotype in South Australia. The 4 South Australian samples in this clade were from the Adelaide Hills and Laura (see samples marked with blue triangle in Figure 3). The two distinct genotypes within Australia are highlighted in green and blue (Figure 3.2). There was more variation between the US samples. The Colorado sample was most closely related to the Australian samples than the other American samples. The remaining 4 samples from the US formed two distinct clusters. The two Phragmites australis samples were genetically very different to the samples of A. donax and formed their own cluster.

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Summary and Conclusions Through AFLP analysis of 170 individual A. donax plants, it was found that at least two distinct genotypes are present in Australia. Less than 1% genetic diversity was found within each genotype, suggesting that all individuals within a genotype come from a single ancestor and the small differences are likely due to somatic mutations. However, the two genotypes differed from each other by 18%, suggesting two separate introductions of A. donax into Australia.

Acknowledgements Thank you to Dr Chris Willams, Dr John Virtue, Stephen Heading, Robin Coles and Peter Boutsalis for assisting with collection of the Arundo samples, Sarah Morran for technical assistance and RIRDC for funding this work. Samples were also provided from Adelaide, Brisbane and Sydney’s Botanic Gardens.

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Figure 3.7: Identical individuals grouped together: the group they are in and number of individuals in that group.

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Group1 CP2 Group2 289 T20 T54 MN7

Only 1% genetic diversity within each group (blue and green) but 18% between the groups

AP8 T32 T44 AP3 246 Group3 Group4 CW9 Group5 261 296 Bris CWA 273 Am1 Am4 Am5 CW7 AP15 Syd1 292 Syd2 300 Am3 Am2 Phrag1 Phrag2

1

Figure 3.8: Dendrogram redone with only one representative from each group of identical individuals. Green and Blue squares show two distinct genotypes amongst samples tested.

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Figure 3.9: Map of SA sample locations. The 4 individuals from the second genotype (blue) are indicated with blue triangles.

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Figure 3.10: Map of all samples. Individuals from the second genotype (blue) are indicated with blue triangles.

C. Managing the weed risk of A. donax Introduction The International Union for the Conservation of Nature (IUCN 2009) recommends appropriate risk management to prevent, detect and treat any escapes of biofuel crops: including monitoring and contingency planning, with viable control procedures. A. donax has an international reputation as a significant weed outside its native range and is subject to noxious weed laws of varying provisions in California, South Africa and New South Wales (Sydney Basin only). However, this report has found the potential weed risk of A. donax in Australia to differ considerably between riparian and non-riparian areas, due primarily to its reproduction and dispersal being limited to vegetative means. The genetic analyses undertaken found no genetic evidence of sexual reproduction having occurred for the sampled populations, with extremely limited genetic variation indicating clones of a very limited number of introductions for Australia (see section 2), as had also been concluded for the USA (Ahmad et al. 2008). In riparian areas it poses a very high weed risk due to the capacity for flood events to disperse vegetative root and shoot fragments to new areas of suitable moist habitat, in which it forms dense monocultures. In areas not subject to flooding (ie. away from floodplains, creeks, drains) A. donax will readily persist in a wide range of climate conditions, but clumps have very slow lateral spread and humans are the main potential dispersal agent (eg. through soil cultivation, grading, slashing).

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Given its substantial weed risk to riparian areas in the landscape, A. donax plantations should be located well away from such areas and managed to minimise the inadvertent dispersal of vegetative material during its establishment, growth, harvest and transport. However, its lack of seed production makes its containment much more manageable than other invasive commercial species, such as tall wheatgrass, buffel grass, radiata pine and olives. It is also an opportune time to establish containment procedures at the initial development of an A. donax industry. Risk management of other potentially invasive commercial plants There has been increasing deliberations about how to address “conflicts of interest” between benefits of invasive commercial plant species versus their costs as weeds of natural ecosystems (Bennett and Virtue 2004, Grice et al. 2008). However, formally-adopted protocols to manage the spread from plantings of invasive commercial plants are rare. Such protocols are more likely to be successful for species of high economic value that are highly visible in the landscape, have a relatively slow rate of spread and are readily controllable (Bennett and Virtue 2004). Protocols which have a statutory basis in law are also more likely to be followed. Six relevant, existing risk management frameworks are summarised below: New Olive Orchards in South Australia Feral olives (Olea europaea) are a major environmental weed in South Australia. The problem originated from seed spreading from abandoned plantings in the late 1800s and early 1900s. Concerns about increased invasion as a consequence of renewed interest in olive production in the mid 1990s led to a statewide olive risk management policy by the Animal and Plant Control Commission (APCC) (Virtue et al. 2008)). A risk assessment system for new olive orchards was developed as a simple MS-Excel spreadsheet to assist local governments in determining whether to approve a proposal (APCC 1999). Under the SA Development Act 1993, if land was not already being used for horticulture then establishing an olive orchard was a change of land use that required approval from local government authorities. Risk to native vegetation was assessed using two criteria: i) the likelihood of olive spread; and ii) the consequences of spread. The likelihood criterion was split into two sub-criteria: a) non-management factors; and b) management factors. Non-management factors ranked the probability of spread of feral olives based on rainfall, surrounding land use and the incidence of soil waterlogging. Management factors considered steps the orchardist planned to follow to minimise dispersal of fruit. These related to bird and fox control, fruit maturity and size at harvest, visibility of fallen fruit, and a buffer zone (20-50 m) around the orchard in which olive seedlings are removed. The consequences criterion had factors considering the distance to significant native vegetation, the presence and control of feral olives in the surrounding landscape, and the presence of existing orchards. A new orchard would not greatly increase the weed risk if there were already many feral olives that were not being controlled and/or if existing orchards were in the area. The outcome of the risk assessment guided local government planning decisions on a new olive orchard. For example, the olive risk management policy recommended that very high risk orchard proposals should not be approved, whereas high risk orchards should only be approved with compulsory management conditions to limit spread. Local governments could not be enforced by the APCC to adopt the olive risk management policy and hence there was varying uptake across South Australia (Virtue et al. 2008). Without ongoing promotion, awareness of the policy and willingness to enforce prescribed management conditions has diminished amongst planners. Feral olives are also widespread in South Australia and control is expensive and rarely enforced, so the policy alone would not substantially reduce spread of feral olives. The policy would have had a much greater chance of success if olives were a new industry for South Australia when it was implemented.

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Leucaena plantings in Queensland Leucaena (Leucaena leucocephala) is a leguminous shrub used as high quality forage for cattle production in Queensland. However, it has also become a serious weed invader in tropical regions, particularly riparian areas. A cross-government policy to reduce the weed threat of leucaena (anonymous 2004) was developed in consultation with the industry. This policy stresses that leucaena should only be planted in situations where containment is feasible, and only for highly managed forage production. Flood zones of creeks, waterways and other drainage lines should be kept clear of the species, with a minimum 200m distance for plantings from these areas to reduce risk of seed spread. Plantings should also be at least 20m from boundary fence lines (anonymous 2004). The policy placed responsibility for control of leucaena ‘escaped’ from forage plantings on the landholder owning the source stand. However, there was no accompanying state declaration of leucaena to enable the enforcement of this policy (but some at the local government level). Industry has taken on responsibility for managing the risk of spread of leucaena through a voluntary code of practice (The Leucaena Network 2009), which refers to the government policy (anonymous 2004). The recently revised code of practice advocates a buffer strip (of strong grass pasture to outcompete leucaena seedlings) for plantings adjacent to creeks/watercourses (distance not specified) and external fence lines (20m as per policy). Leucaena plantings should be fully fenced to reduce stock spread of seed, and regularly cut or grazed to reduce seed set. Genetically modified plants Australia manages any risks that genetically modified plants may pose to the environment or human health through the Gene Technology Act 2000, administered through the Office of the Gene Technology Regulator. This includes compulsory risk management provisions for field trials of such plants. Of relevance to A. donax is the buffer distance of at least 50m from natural waterways that was required by OGTR for past trials on GM perennial ryegrass and fescue (where plants were to be removed from field before flowering) and sugarcane. Category 2 plants in South Africa (ARC 2009, Henderson 2001) Regulations introduced in 2001 for South Africa’s Conservation of Agricultural Resources Act, 1983 included plant species being able to be placed in “Category 2”, which enables legal provisions to contain the spread of invasive economic crops. Category 2 plants are to be retained/grown only in special areas demarcated for that purpose, and those outside such areas have to be controlled. An Executive Officer under the Act determines such special areas and the conditions under which the Category 2 plants are cultivated and controlled within the area. All reasonable steps have to be taken to prevent seed or vegetatively reproducing material being dispersed outside the demarcated area, with such propagative material only being able to be sold to and acquired by land users of areas demarcated for the growing of that species. Unless otherwise authorised, Category 2 plants may not occur within 30 m from the 1:50 year flood line of watercourses or wetlands. Category 2 plants in include various Acacia, Eucalyptus and Pinus species grown for firewood and timber. A. donax is classed as a “Category 1” plant across South Africa, making its cultivation, trade and movement illegal. Gamba grass management in Northern Territory Gamba grass is a tussock-forming, tall perennial grass used for as pasture for cattle in northern Australia. However, it has been found to be highly invasive with the ability to have significant negative environmental impacts in savanna landscapes. Due to its very high weed risk it has been declared under the Northern Territory’s Weeds Management Act 2001. Areas where it is already wellestablished are declared as “Class B”, where growth and spread are to be controlled but eradication is not required. Dispersal is predominantly by seed, and a management guide (anonymous 2009) gives

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guidance on how to limit seed production and spread. A buffer zone is required where seed production is to be prevented, of 20m width in Class B areas and 40 m when adjoining properties in Class A (ie. eradication) zones. Harvest, movement and planting of seed is illegal throughout the Northern Territory. Distichlis spicata in South Australia Distichlis spicata is a salt-tolerant grass native to the USA, which has been investigated by NyPa Australia Pty Ltd for their potential use in saline agriculture and as amenity plantings using saline irrigation water (www.nypa.com.au). The species is single sex, perennial, rhizomatous with a C4 photosynthetic pathway. A weed risk assessment indicated the potential for the species to spread vegetatively into wetlands and saltmarsh areas in South Australia, but spread would be slow as all lines being investigated were male sex only, so no seed production would occur. In recognition of the potential for economic and environmental benefits, the Animal and Plant Control Commission (APCC) determined to declare female and mixed sex lines of D. spicata for movement and sale. For the two lines being investigated (NyPa Forage and NyPa Turf), APCC requested that control trials be undertaken by NyPa so that vegetative spread of D. spicata could be contained. A national herbicide permit for the species was subsequently obtained by NyPa.

Arundo donax risk management Plant species in Australia posing significant weed risks can be regulated through the various noxious weed Acts of the States and Territories. These are policy decisions for each government, taking account of such factors as: -

a weed species’ management costs (that would be borne by individuals, industries, government agencies and the wider community); benefits from limiting unwanted spread of a plant species (economic, environmental and social impacts avoided); feasibility of containment; benefits from commercial use of a plant species; and industry-led versus government-mandated management.

As such it is not appropriate for this document to mandate a particular management approach to be consistently implemented for A. donax across Australia. Rather, the following is a guide for each State/Territory to consider in determining their policy on A. donax. Weed Risk Management Guidelines Preventative measures 1.

Declaration of A. donax A. donax poses a high weed risk to riparian ecosystems across a wide range of climate zones in Australia, with potential for substantial impacts on biodiversity, access, fire regime, water use and infrastructure. Its current, naturalised distribution is small compared to many existing declared plants, although historical windbreak, soil stabilisation and ornamental plantings can be commonly found in urban and rural areas. Declarations for control, movement and sale under the provisions of the various State and Territory noxious weed acts would give a legislative basis to regulating the cultivation and containment of A. donax. Permits giving exemptions could then be provided for commercial plantings of A. donax, provided they met certain conditions (see below).

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Noxious weed agencies would need to consider their response to existing wild and cultivated stands of A. donax in their jurisdiction. It would be inconsistent to regulate future plantings due to weed risk yet not require control of existing stands. However, depending on contents of noxious weed Acts, there may be scope to target requirements for control to certain areas in the landscape, particularly those infestations currently within or adjacent to riparian areas. For example, Athel pine (Tamarix aphylla) has been declared for control within 100m of watercourses in certain parts of South Australia. Cost of control for declared plants is normally borne by the landholder who has the weed on their property. Under existing noxious weed acts a new A. donax industry would not have a legal responsibility for control of existing stands not present on their land. 2.

Permits for commercial cultivation of A. donax Permits for the cultivation of A. donax could be provided by the relevant noxious weed agency to landholders. These would be provided on a case by case basis, excluding them from the requirement to control, move or sell the plant, provided they abide by permit conditions to prevent inadvertent spread (see below). Site inspections would need to be undertaken on at least an annual basis by noxious weed officers to ensure that permit conditions are being met.

3.

Location of plantings outside riparian zones A. donax should not be established in parts of the landscape where there is a risk of it spreading to and within riparian areas. This includes areas subject to significant flooding events – a 1 in 50 year flood frequency is suggested as the guideline to determine boundaries to exclude A. donax cultivation. A possible exception could be where soil engineering is proposed to create levees to prevent entry of floodwaters and/or substantially slow their velocity so that the probability of stem or root fragments of A. donax dislodging is low.

4.

Containment and buffer zones A. donax should be planted a minimum of 20 m from natural watercourses and constructed drains. This is less than for other case studies listed above, due to the absence of seed production by A. donax. A buffer zone of a minimum of 10 m should be established around the perimeter of plantings, with encroachment of A. donax into this zone prevented by physical and/or herbicidal control. A fenceline beyond the 10 m should be established to prevent access by the public, livestock and large feral herbivores (eg. pigs, deer). In Hornsby Shire in Sydney, NSW, it is a requirement that A. donax, as a Class 4 noxious weed, must be prevented from growing within 10 m of bushland (www.hornsby.nsw.gov.au). Further containment of any dislodged stem material could be achieved by soil contours around the perimeter, to contain and direct water movement into and out of the planting.

5.

Control of any escapees An initial survey should map any existing A. donax (planted and wild) in proximity to a proposed plantation. A minimum of a 1 km land radius, 5 km length of the drainage line/watercourse downstream from the planting site and 5 km length of roadsides away from the site should be surveyed. This will provide a baseline for monitoring and detecting any future spread.

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Control of any escapees should be through physical removal, including all rhizome material. With annual monitoring, large infestations required herbicidal treatment (with glyphosate) would be unlikely to occur. Annual surveys should be undertaken (covering the same sites as in the initial survey) to detect any escapes of A. donax. If found, these should be mapped and promptly treated by physical removal or use herbicidal treatment. The cost of surveys and any required control could be met by an industry levy. For example, Williams et al. (2008b) calculated that a weed risk monitoring levy of 50 cents/oven dry tonne of A. donax collected at the factory gate would have insignificant effects on contracted grower returns. As a further measure, a bond could be required in the event that a plantation was abandoned, to cover the costs of removal. 6.

Harvest, transport and processing Chipping is a very effective treatment to reduce sprouting of both rhizomes and stems (Boose and Holt 1999). Hygiene practices should be undertaken to prevent inadvertent spread of A. donax during harvesting, transport and processing. Harvesting equipment should be cleaned of any fragments by brushing, air or water pressure sprays, prior to leaving a plantation. A. donax fragments on the ground after cleaning harvesters and loading trucks should be raked and burnt. A. donax declared under a noxious weeds act would require a permit for transport on roads. Harvested material should only be moved in sealed containers (or fully tarped enclosed loads). The processing and use of A. donax material needs to ensure that it loses its capacity for vegetative regeneration from dormant buds in leaf axils.

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Chapter 4: Evaluation of Arundo donax for pulp/paper David Paul1, Chris Williams2 and Tom Rainey3 1

FibreCell Australia Pty Ltd, 187 Jeffcott St, North Adelaide, SA 5006 SARDI, GPO Box 397 Adelaide, SA 5001 3 Sugar Research and Innovation, Queensland University of Technology Gardens Point Campus, Centre for Tropical Crops and Biocommodities, H block, level 3, 2 George St, Brisbane, Queensland, Australia 4000. 2

Introduction Many methods are used around the world to pulp, bleach and convert fibre/biomass feedstocks including A. donax to different types of paper. Over 30 papers have been published using A. donax as raw feedstock for pulp/paper making (Byrd 2000; Shalatov et al. 2001; Shatalov and Quilho 2001; Lewis and Jackson 2002; Shatalov and Pereira 2002; Shatalov and Pereira 2004; Shatalov and Pereira 2005; Paul and Williams 2006; Shatalov and Pereira 2006; Shatalov et al. 2006; Coelho et al 2007). Two methods were chosen to examine the pulp/paper making options using A. donax stems as feedstocks. The objectives of the pulp studies in this project were: (a) to assess the commonly used, worldwide practice of kraft pulping to extract pulp from A. donax and impacts on paper quality, and (b) to establish the impact of replacing part of the fibre input at the Millicent pulp/tissue and sanitary products Mill with A. donax using the Mill’s existing bisulphite pulping process (also known as the Magnifite process).

Methods and Results The full reports, giving detailed results of the kraft pulping and ECF (elemental chlorine free) bleaching and for the bisulphite process are given in Appendices 4.A and 4.B, respectively, at the end of this chapter.

Discussion The objectives of our pulp studies were: (a) to assess the commonly used, worldwide practice of kraft pulping to produce pulp from A. donax and the impacts on paper quality, and (b) to establish the impact of replacing part of the fibre input at the Millicent pulp/tissue and sanitary products Mill with A. donax using the Mill’s existing bisulphite pulping process (also known as the Magnifite process). Two pulping studies of A. donax were conducted. The initial study assessed the suitability of Millicent Mill’s existing bisulfite pulping process for pulping A. donax. In the initial study, it was found that the pulp could not be bleached to a level where it was suitably “white” for hygiene products, such as toilet paper and facial tissue. Residual dirt could also be observed in the pulp, which also reduces the attractive appearance of tissue paper. Consequently, a second study was performed by the Central Pulp and Paper Research Institute, Saharanpur, India. They were contracted to conduct the kraft pulping of A. donax stem and bleaching of A. donax using an environmentally benign chlorine free (ECF) bleaching. They were able to achieve a substantial improvement in pulp brightness using the kraft process rather than the sulphite process as evaluated in the contract to CSIRO Material Science and Engineering (see Appendices 4.A and 4.B, for complete reports). On the positive side, using the kraft process the brightness of A. donax pulp increased from c. 62 to 86 without seeking any optimisation of the pulping conditions. This means that it is possible to produce a bright sheet of paper, which is an important property for hygiene products, such as tissue. The

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strength properties of paper produced from the pulp are also important. The tear strength of A. donax pulp (8.9 mN/m2g) was higher than conventional eucalypt (6 mN/m2g 1 which is a more natural substitute for A. donax given its short fibre length) and compared to the pine produced at the Millicent Mill (8.3 mN/m2g, Appendix 4.B). Tests by Shatalov et al. (2001) reveal that the A. donax fibre length is generally around 1mm in length making it comparable to eucalyptus pulp in that regard. On the negative side, using the kraft process without any optimisation of process conditions, the pulp yield remained low at 37% and the tensile strength was fairly low in the Australian context in comparison to where the work was performed (i.e. India). However, low tensile strength is not as detrimental for tissue products as for photocopier papers and it is likely to improve the softness properties of the tissue/toilet paper. The dirt content was not assessed in the second study. Agricultural fibre such as A. donax experiences similar but fewer adverse issues with regard to drainage and dirt than sugarcane bagasse and wheat straw which are used successfully for 5-10% of global paper production. Industrially, agricultural fibre undergoes additional treatment prior to pulping in order to overcome these issues. Using the kraft process, A. donax appears suitable for lower quality generic grades of tissues for both facial tissues and toilet paper. It appears it will also be possible to make generic photocopier papers from A. donax. Further major research work as detailed below is needed to develop methods to make premium grades of paper from A. donax. Printing and writing papers make up about 20% of Australia’s annual production of paper, whereas tissue and towelling makes up about 7% of the total. However, using the bisulphite process (only c. 2% of world pulping processes use this) as used at the Millicent Mill, the use of A. donax in tissue and sanitary products may have to be restricted to levels well below 20% of the current Pinus radiata fibre feedstock used. Future work should explore the potential to use A. donax to replace part of the imported Eucalyptus hardwood feedstock used in paper making. The short fibre length of A. donax pulp makes its properties more suitable for substituting for a eucalypt pulp than for a pine pulp. The kraft process offers a better option for technically sound pulp but the economics and environmental impacts for construction of a new kraft mill would need to be investigated.

Conclusion: Arundo donax is a good source of fibrous raw material for making quality paper. The chemical demand in cooking and bleachability of pulp is satisfactory. The prospects for producing pulp and paper from A. donax are fair, using the kraft process. Appendix 4.A: Kraft pulp report, Central Pulp and Paper Research Institute, India Appendix 4.B: Bisulphite pulp report, Peter de Morton, N Vanderhoek and Michael Wedding, CSIRO Material Science and Engineering, Clayton, Victoria

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Chapter 5: Pretreatment and fermentation studies for second generation ethanol production from Arundo donax Authors: Peter Rogers1, Young-Jae Jeon1, Chris Williams2 1 Biotechnology Department, University of NSW, Sydney, NSW, Australia 2000 2 SARDI, GPO Box 397 Adelaide, SA 5001

Summary Laboratory- scale studies with 10% (w/v) A. donax have demonstrated that up to 240 L ethanol/dry tonne of A. donax can be produced with acid/enzyme hydrolysis and 224 L/dry tonne with alkali/enzyme pre-treatment. The presence of inhibitory compounds was identified in both hydrolysates with the acid/enzyme process showing higher concentrations of the more toxic aromatic compounds (furfural, levulinic acid). However, although acetate concentrations were relatively high (4.8 g/L) following acid /enzyme pre-treatment, the concentrations of other inhibitory compounds in A. donax (eg formate, levulinic acid, furfural) were lower than in wheat straw, bagasse and sorghum straw (Rogers, unpublished results).Our results, although preliminary, show A. donax to be in the premium group for biomass feedstock quality and yield for ethanol production (with wheat and sorghum straw and bagasse). Future studies need to be funded for larger scale R&D, with optimised pre-treatment and fermentations, as well as micro-organisms conditioned to various inhibitors, these techniques are likely to result in significant improvements in ethanol yields and productivities from A. donax of up to 300-350 L/oven dry tonne of biomass.

Introduction In the present evaluation, A. donax was evaluated as a potential cellulosic raw material for the production of fuel ethanol. Laboratory–scale pretreatment and fermentation studies have been carried out, the latter using a recombinant strain of Zymomonas mobilis which can convert both glucose and xylose to ethanol.

Materials and Methods Preparation of A. donax The A. donax sample used in this study was provided by Dr. Chris Williams from the South Australian Research Development Institute (SARDI, South Australia, Australia) (Williams et al. 2008). A. donax biomass was one year old regrowth (stems with leaves) from clearfell, grown at Barmera, SA (Loveday rootstock from Williams et al 2008). The raw material had the following sugar composition: cellulose 42.5 %, hemicellulose 31.2% based on dry weight. The raw material was ground to particle sizes of 1-5mm. To determine sugar recovery yields from acid/enzyme and alkali/enzyme hydrolyses, the material was kept in a 65o C oven overnight to maintain a constant dry weight prior to the pretreatment. Dilute acid pretreatment and enzyme hydrolysis To evaluate sugar recovery yields from the hemicellulose and cellulose fractions, dilute acid pretreatment was performed in 2% H2SO4 (v/v) with 10% (w/v) raw material at both 121o C and 134o C for 30 or 60 min. Prior to enzyme hydrolysis, the pH of the acid pretreated hydrolysates was adjusted at 5.0 using solid Ca(OH)2. Hydrolysis of the cellulosic component of the raw materials was evaluated using 0.2 and 2% cellulase (Novozyme: NS50013) and 0.4 and 4 % β-glucosidase 72

(Novozyme: NS50010) designed to release glucose. The Novozyme cellulase 50013 contained 700 EGU (endo-glucanase units)/ g of total cellulase; β-glucosidase activity of Novozyme 50010 was 250 CbU (cellobiase units)/ g. The enzyme hydrolyses were carried out at 50o C and 60o C with shaking at 180 rpm for 22 h. Recovery of sugars (%) was calculated from total sugars in the final acid/enzyme hydrolysate compared to the total sugars from the initial hemicellulose and cellulose in the dry weight samples.

Alkali pretreatment and enzyme hydrolysis Alkali pretreatment was performed under similar conditions to dilute acid pretreatment using 2% (w/v) NaOH with 10% (w/v) substrate at 134o C for 60 min. Following the alkali pretreatment, the solublised lignins were removed by filtration and then an equal volume of deionised water added into the solid slurry. Prior to the enzyme hydrolysis, the pH was adjusted to 5.0 using 2M H2SO4. For the enzyme hydrolysis 2% xylanase (Novozyme NS 50030), 2% cellulase (NS50013) and 4% βglucosidase (Novozyme NS50010) were added and the reaction was carried out at 50oC for 22 h with 180 rpm. The Novozyme xylanase 50030 contained 500 FXU (fungal-xylanase units) /g. To monitor the enzyme reactions, xylan (Sigma-Aldrich, USA) and Sigmacell cellulose (Sigma-Aldrich) were used as controls.

Strain for ethanol production and its maintenance The recombinant strain of Zymomonas mobilis ZM4 (pZB5) (Joachimsthal et al. 2000) was used in this study for fermentability tests of the lignocellulosic hydrolysates derived from the raw material via acid/enzyme and alkali/enzyme hydrolyses. The recombinant strain which can utilise both xylose and glucose for ethanol production was kindly provided by Dr. Min Zhang, National Renewable Energy Laboratory, Golden, Co. under a Material Transfer Agreement. The strain was routinely cultured at 0o C on agar plates containing 20 g /l xylose, 5 g/ l yeast extract and 20 µg /ml tetracycline.

Preparation of acid/enzyme hydrolysates for fermentation The acid/enzyme treated hydrolysates were adjusted to pH 5 using 3M NaOH. To separate the liquid hydrolysate, the solid fraction (unhydrolysed fiber and gypsum (CaSO4)) was removed by centrifugation at 7000 g for 20 min.

Preparation of alkali/enzyme hydrolysates for fermentation The alkali/enzyme hydrolysates were adjusted to pH 5. To separate the liquid hydrolysate, the solid fraction of unhydrolysed fiber was removed by centrifugation at 7000 g for 20 min.

Inoculum preparation and fermentation media Inocula for fermentation were prepared by plating Z. mobilis ZM4 (pZB5) from frozen cultures onto the agar plates whose compositions are described above. A single colony was selected and used to inoculate 10 ml of 1st seed medium composed of per liter: 25 g xylose, 10 g yeast extract and basal minerals (1 g MgSO4∙7H2O; 1g (NH4)2SO4; 2g KH2PO4). When an optical density of A660= 0.8~1.0 was reached, a 1% (v/v) aliquot was used to inoculate the second seed culture medium composed of acid/enzyme or alkali/enzyme hydrolysate supplemented with additional nutrients per litre: 2.5 g glucose, 12.5 g xylose, 2.5 g yeast extract and basal minerals (concentrations as above). When an optical density of A660= 0.8~1.0 was reached, a 10% (v/v) aliquot of second seed culture was used to inoculate the main fermentation medium. The fermentation medium was composed of the acid/enzyme or alkali/enzyme hydrolysates supplemented with yeast extract (5 g/l). For the plasmid maintenance all media included 20 mg/l tetracycline.

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Fermentation conditions Fermentations were carried out in 100 ml Erlenmeyer flasks with working volumes of 50 ml. The batch cultures were performed at 30o C and initial pH 5.0 without shaking as agitation was provided by gas release during fermentation. Samples were taken at various times to determine biomass, glucose, xylose and ethanol concentrations.

Analytical procedures Acid/enzyme hydrolysate samples were analysed for glucose, xylose, arabinose and degradation products including acetate, furfural, hydroxymethylfuraldehyde (HMF), levulinic acid, and formate by HPLC using an Aminex column HPX-87H (300x 7.8) (Bio-Rad, Richmond, CA) equipped with a refractive index detector and a computer interfaced electronic integrator using the refractive detector. Separations were performed at 50o C and eluted at 0.6 ml/ min using 5 mM H2SO4. Growth was measured turbidometrically at 660 nm (1 cm light path). Dry cell mass was determined by conversion of optical density values at 660 nm to dry cell weight using dry cell weight conversion constant value for ZM4(pZB5) (OD660nm 0.05= 15 mg per liter, Kim et al., 2000). Fermentation samples were analysed for glucose, xylose and ethanol concentrations by HPLC using a refractive detector under the conditions described above. Standards containing analytical grade components were used periodically to confirm calibration accuracy.

Results Both acid/enzyme and alkali/enzyme pretreatment strategies have been followed to extract fermentable sugars using 10% (w/v) A. donax. This biomass concentration was selected as higher concentrations resulted in a semi-solid state making sugar recovery studies difficult under laboratory scale conditions (shake flasks). Higher biomass concentrations have been reported in commercial systems using countercurrent reactors with screw feeding of solids. However, such systems have been designed for large-scale acid/alkali hydrolyses and were not available in the present evaluation. Acid/enzyme hydrolysis The results of acid hydrolysis at 121o C for 30 min followed by addition of enzymes (2% cellulase and 4% β-glucosidase) at 60o C, pH 5.0 are shown in Figure 1. Following acid hydrolysis, 24 g/l xylose, 2 g/l arabinose and 2 g/l glucose were released. Subsequent enzyme hydrolysis resulted in an increase in the glucose concentration to 8 g/l. The effect of an increase in the temperature/time of acid hydrolysis to 134o C/60 min, followed by the addition of the same enzyme concentrations is shown in Figure 2. Similar xylose and arabinose concentrations were achieved, but the glucose concentration was increased to 18 g/l. In both cases the glucose released from 10% (w/v) Sigmacell (pure cellulose) was approximately 30 g/l indicating only partial cellulose hydrolysis under these conditions.

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o

Figure 5.1: Sugar extraction using 2% H2SO4 at 121 C, 30 min followed by 2% cellulase and 4% o glucosidase (Novozyme) treatment at 60 C, pH 5.0 and 180 rpm for 22 h.

Sigmacell was used as a control to determine the effectiveness of the enzyme hydrolysis. Note: The sample taken at 0 h is an acid hydrolysate prior to adjustment of pH for enzyme hydrolysis.

o

Figure 5.2: Sugar extraction from A. donax using 2% H2SO4 at 134 C, 60 min followed by 2% o cellulase and 4% β-glucosidase (Novozyme) treatment at 60 C, pH 5.0 and 180 rpm for 22 h.

Sigmacell was used as a control to determine the effectiveness of the enzyme hydrolysis. Note: The sample taken at 0 h is an acid hydrolysate prior to adjustment of pH for enzyme hydrolysis. The effect of reducing the enzyme hydrolysis temperature from 60o C to 50o C, while maintaining all other conditions constant, is shown in Figure 3. As expected, similar xylose and arabinose concentrations were achieved. However, for 10% w/v biomass, the glucose concentration after 22 h was increased from 18 g/l to 25 g /l. An increase in the glucose release from Sigmacell (10% w/v) was also evident with concentration increasing from approximately 30 g /l to greater than 45 g/l (see Figure 5.3). Interestingly a further evaluation study at 15% (w/v) substrate loading of A. donax under the same conditions showed that glucose and xylose concentrations each of 32 g/l could be achieved (see also Figure 5.3).

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As enzyme costs are a major component in the cost of converting biomass such as A. donax to ethanol, a further evaluation was carried out with a 10 fold reduction in added enzymes, viz. 0.2 % cellulose and 0.4 % ß-glucosidase at 50o C. As shown in Fig 4, this resulted in a decreased release of glucose (11 g/l), paralleled by a decreased release of glucose from Sigmacell (17 g /l). This indicates that enzyme concentrations greater than 0.2% cellulose and 0.4% ß-glucosidase are necessary to achieve higher glucose release.

Figure 5.3: Sugar extraction of A. donax using 2% H2SO4 at 134o C, 60 min followed by 2 % cellulase and 4 % β-glucosidase (Novozyme) treatment at 50o C, pH 5.0 and 180 rpm for 22 h.

Sigmacell (pure cellulose) was used as a control to determine the effectiveness of the enzyme hydrolysis. Note: The sample taken at 0 h is the acid hydrolysate prior to adjustment of pH for enzyme hydrolysis.

o

Figure 5.4: Sugar extraction using 2% H2SO4 at 134 C, 30min followed by 0.2% cellulase and o 0.4% β-glucosidase (Novozyme) treatment at 50 C, pH 5.0 and 180 rpm for 22 h.

Sigmacell (pure cellulose) was used as a control to determine the effectiveness of the enzyme hydrolysis Note: The sample taken at 0 h is an acid hydrolysate prior to adjustment of pH for enzyme hydrolysis. 76

Alkali/enzyme hydrolysis To determine whether or not an alkali/enzyme pretreatment might be better than the acid/enzyme pretreatment conditions reported above (see Figure 5.3), an experiment was carried out under similar environmental conditions with addition of 2% NaOH. In this latter case, 2% xylanase was also added to facilitate release of xylose. This was not released under alkali conditions as the addition of 2% NaOH acts to solubilise the lignin rather than release the xylose from the hemicelluloses (as is the case for acid hydrolysis). These results are shown in Figure 5 with a final glucose concentration of 23 g/l and xylose of 12 g/l. By comparison with acid /enzyme hydrolysis results shown in Figure 3, the glucose concentration was similar although the xylose concentration was 45% less with alkali/enzyme hydrolysis.

o

Figure 5 5: Sugar extraction of 10 % (w/v) A. donax using 2% NaOH at 134 C, 60 min followed o by 2 % cellulase, 2% xylanase and 4 % β-glucosidase (Novozyme) treatment at 50 C, pH 5.0 and 180 rpm for 22 h.

Sigmacell (pure cellulose) and xylan (xylose-based sugar) were used as controls to determine the effectiveness of the enzyme hydrolysis. Note: The sample taken at 0 h is an alkali hydrolysate prior to adjustment of pH for enzyme hydrolysis Fermentation results Fermentation data using a recombinant strain of Zymomonas mobilis ZM4 (pZB5), capable of using both glucose and xylose, are shown in Figure 6 and 7. The fermentation profiles with the acid/enzyme hydrolysate from 10% (w/v) loading are shown in Figure 6 and it is evident while the glucose was fully utilized after 48 h, that appreciable xylose still remained at this time. A final ethanol concentration of 17 g/l was achieved after 72h. By comparison, the fermentation profiles for the alkali/enzyme hydrolysate showed a more rapid uptake of glucose (fully utilized after 24 h), a greater uptake of xylose and a final ethanol concentration of 19 g/l after 30 h (see Figure 7).

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Presence of inhibitory compounds A comparison of potential inhibitory compounds from both these hydrolysates is shown in 3. 1. This indicates that while acetate and formic acid concentrations were lower in the acid/enzyme hydrolysate, higher concentrations of levulinic acid, hydroxymethylfuraldehyde (HMF) and furfural occured when compared to those in alkali/enzyme hydrolysate. This may explain the reason in the latter case for the higher rate of ethanol production and its increased concentration. An earlier article by Thomasser et al. (2002) outlines the effects that inhibitors can have on ethanol producing bacteria.

Figure 5.6: Fermentation profile of ZM4 (pZB5) using A. donax acid/enzyme hydrolysate derived o from 10% (w/v) substrate loading using 2% H2SO4 at 134 C for 60 min followed enzyme o hydrolysis at 50 C for 22 h using 2% cellulase and 4% β-glucosidase.

Figure 5.7: Fermentation profile of ZM4 (pZB5) using A. donax alkali/enzyme hydrolysate o derived from 10% (w/v) substrate loading using 2% NaOH at 134 C for 60 min followed enzyme o hydrolysis at 50 C, pH 5.0 for 22 h using 2% xylanase, 2% cellulase and 4% β-glucosidase.

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Table 5.1(a): Inhibitory compounds derived from acid/enzyme hydrolysate (10% w/v) of A. donax.

Inhibitory compounds

Concentration (g/l)

Acetic acid

4.8

Formate

0.5

Levulinic acid

0.3

HMF

0.04

Fufural

0.7

Table 5.1(b): Inhibitory compounds derived from alkali/enzyme hydrolysate (10% w/v) of A. donax.

a

Inhibitory compounds

Concentration (g/l)

Acetic acid

6.0

Formate

6.7

Levulinic acid

NDa

HMF

ND

Fufural

ND

: Not detected due to being too low to be determined

Discussion and Conclusions The pretreatment and fermentation studies on 10% (w/v) A. donax have shown that higher total sugar concentrations can be achieved with an acid/enzyme process when compared to an alkali/enzyme process due primarily to a greater release of xylose in the former case. However both the ethanol productivity (g/l/h) and the ethanol yields were higher for the alkali/enzyme hydrolysis possibly due to the lower concentrations of aromatic inhibitory compounds. Steam explosion may be another suitable method to break bonds in cellulose, and expose simple sugars to enzymes, however this process is often more energy intensive and current large scale R&D studies are largely focused on acid/enzyme or alkali/enzyme pretreatment. Major commercial and pilot scale facilities using cellulosic raw materials for fuel ethanol production (second generation processes) are now under construction in the US and Europe. Projections by the US Department of Energy (DOE) are by 2020 that twice as much ethanol will be produced from cellulosic biomass as from corn. Funds of close to US$1BN have allocated by DOE to a number of companies to evaluate various technologies and feedstocks with projected production

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scales of 100-200 million L/annum of ethanol. Dupont Danisco for example announced in May 2008 that US$140M be invested in a factory to produce ethanol from corn stover and/or sugar cane bagasse using recombinant strains of the bacterium Zymomonas mobilis. In Europe, the Dutch company Nedalco announced in 2008 that a plant capable of producing 200 million L/annum of ethanol would be established using wheat bran as raw material and a recombinant strain of yeast for the fermentation. In Australia, Government funding of A$14m has been allocated to a Biofuels SubProgram within the National Collaborative Research Infrastructure Strategy (NCRIS) for 2006-2011, and more recently A$15m has been awarded to a number of companies for 2nd Generation biofuels (eg. ethanol from biomass, biodiesel from algae). Current ethanol production costs from cellulosic biomass depend critically on raw material and pretreatment costs (particularly enzyme costs), as well as operational scale. In addition it is estimated that CO2 emissions will be reduced by 60-80% compared to those of non-renewable fuels. Since fossil oil is expected to increase in price, over US$80/barrel, economics for biomass to ethanol is likely to become more profitable. Our preliminary estimates indicate an Internal rate of return for an A. donax to Ethanol factory in SA , with ethanol at 50 cents/L at the factory gate, to be 17% (moderately attractive to investors, see Chapter 9, RIRDC report). Further details on the bioethanol process development and future R&D strategies are provided by Olssen et al. (2007) and the recent ATSE report (2008). The results are summarized in the following Table 5.2. The ethanol yields expressed as L/dry tonne of A. donax and show values of 240 L/dry tonne for the acid /enzyme process and 224 L/dry tonne for the alkali/enzyme process for the laboratory scale evaluations. Based on the theoretical yields reported for other biomass sources (Galbe and Zacchi 2007), and assuming that 80% yields for sugar and ethanol production could be reached using controlled and optimized processing conditions, it is considered that final ethanol yields of 300-350 L/dry tonne could be achieved with A. donax hydrolysates. Our studies indicated that A. donax be classed in the premium group of biomass feedstocks for quality and yield of ethanol (with wheat and sorghum straw and bagasse) and superior to Eucalyptus species, pine (Pinus radiata) and oil mallee. Further research studies on a larger scale (10-15 L capacity) under controlled fermentation conditions are needed to confirm these increased yield projections and achieve higher ethanol concentrations from A. donax feedstock. Table 5.2: Summary of pretreatment and fermentation results for 10% (w/v) A. donax.

Acid/enzyme

Alkali/enzyme

66

50

0.39

0.48

Ethanol yield (% theoretical)

76

94

Max. ethanol productivity (g/l/h)

0.4

0.8

Ethanol (L/tonne)

240

224

a

Sugar yield (%)

b

Ethanol yields (g/g)

a

: Sugar yields are based on initial cellulose and hemicellulose in A. donax. : Ethanol yields are based on glucose and xylose utilised in fermentations

b

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Possible process diagrams for A. donax are shown in Figures 5.8 and 5.9.

nd

Figure 5.8: Schematic diagram of 2 generation ethanol production process using acid/enzyme hydrolysis used in this study.

nd

Figure 5.9: Schematic diagram of 2 generation ethanol production process using alkali/enzyme hydrolysis used in this study.

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Chapter 6: Arundo donax in the upper South East of South Australia Dr Ian Black, Principal Economist and Dr Chris Williams, Senior Scientist, SARDI, GPO Box 397 Adelaide, SA 5001

Summary The cost of growing A. donax in the upper South East of South Australia, in the Meningie Downs area was assessed. The concept was of a large complex of plantations on rented land managed by a growing company in contract to a conversion factory. Three types of production systems were envisaged: dryland, conventionally irrigated and “naturally irrigated” through the plant’s roots reaching the moderately saline water table. With nutrients commercially supplied, the average factory gate price of the three systems was $65/oven dry t of A. donax. If a substantial part of the plant’s nutrient requirements were returned from the processing factory after A. donax conversion at no cost to the growing company, the average price was calculated to be $53/oven dry t. At A$60/ dry t at the factory gate and 500,000 oven dry tonnes supplied per year to a conversion factory, Adx shows potential to offer South Australia a new industry to produce either bioethanol and lignin, or pulp/paper, provided 3 years of near-market agronomy research and development and upscaling is funded and conducted. Preliminary estimates indicate an internal rate of return on funds employed of 22 % p.a. for the ethanol and lignin enterprise and 18% p.a. for the pulp/paper enterprise, based on central price estimates. Electricity generation plus biochar production using A. donax as feedstock at a cost of $60/oven dry t and a slow pyrolysis process does not appear to represent a sound private enterprise investment, based on the preliminary analyses. It is expected that the commercial potential of non food, cellulosic crop feedstocks grown on marginal lands for conversion to biofuels will increase in future if the price of fossil fuels rises significantly and if the crops can attract carbon credits.

Introduction The profitability of growing A. donax and converting it to usable products is of paramount importance in determining whether or not this possible new industry has a future. • •

A general requirement that this non-food production not compete with food production was noted. A further assumed requirement was that an industry based on A. donax production requires reasonable continuity of supply of the raw material.

These requirements were met through economic analysis of an industry based in the Meningie Downs area, following land analysis and advice from D. Maschmedt and colleagues (SA Dept Water Land and Biodiversity Conservation). This area is under-laid with a moderately saline water table which is unsuitable for producing high value irrigation crops, but suitable for A. donax production, and has a relatively high annual rainfall (450 to 500 mm). The land currently carries sheep and cattle at low density. Analyses proceeded in 2 stages: •

A preliminary analysis leading to indicative factory gate prices for production of A. donax on different classes of land/production systems: – dryland, “naturally” irrigated and conventionally flood irrigated (see (1), below), with a key requirement that the operators of the production systems required a minimum internal rate of return (IRR) of 15%.

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•

Indicative internal rates of return were calculated for enterprises producing bioenergy and other products or paper pulp using best estimates of capital and running costs, and output prices.

A. A preliminary analysis leading to indicative factory gate prices for production on different classes of land Key Assumptions Factory sited in the Meningie Downs Area: The Meningie Downs Land System is a gently undulating sand plain with low to moderate irregular sand dunes and isolated low stony rises. Saline water tables underlie the System and are near the surface in some low-lying depressions. Sandy soils predominate. They range from deep sands to sand over sandy clays. Shallow stony soils are minor. The Meningie Downs Land System comprises mainly sandy soils, with clayey subsoils on flats, but usually extending below a metre on sand dunes. Natural fertility is low, and water repellence and wind erosion are moderate to high limitations. Although some cropping is carried out, grazing of perennial pastures is the most extensive land use (McCord, 1995). A detailed examination of the report (loc. cit.) indicates that 90 % of the area is either flat or slightly undulating sandy topsoils that appear suitable for cropping, subject to necessary amendments to overcome water repellence. •

•

•

• • • •

Three types of growing enterprise were identified: 1. Dryland production 2. A. donax production without irrigation in areas where the roots have reached the shallow saline watertable, thus being “naturally irrigated” 3. Flood irrigated A. donax production using the saline watertable, requiring a subsoil drainage network to remove accumulating salt from the root zone 1. The system is approximately 44,000 ha in area (McCord, loc. cit.). However, the system would probably be unable to supply the full production requirements of the factory (1 M t fresh weight A. donax per annum.), due to some land holders not agreeing to the lease or purchase of land, the unsuitability of some soils, and relatively low production from dryland areas where the crop’s roots are unable to reach the underlying water table. Hence transport of cut A. donax from crops grown on similar land systems for up to 100 km from the proposed factory may be needed. The land is leased, at an annual rent of $150/ha. This assumption is based on ABARE published land values for their “SA South East region” of A$2200/ha (mean value of last 5 years of published data). The land is considered to be below average, hence a mean purchase value of A$1500/ha is assumed, and an annual rental price based on 10% of this figure. Note that this is equivalent to an amortisation period of 10 years if outright purchase of the land becomes the strategy. The production is undertaken by a growing company, using the leased land and sub contracting growers in order to achieve economies of scale and efficiency. The land may require amelioration to overcome the surface soil water repellent properties, using low salt content clay (note that in the costings, Tables 6.1 & 6.2 below, the assumption has been made that all land requires amelioration). In areas where it is thought that the crop’s roots can reach the water table, the land will be deep ripped to expedite this process. Planting is based on cut stems from existing stands rooting at the nodes, with the first year’s production not harvested, to allow the stand to more rapidly increase in density in the second and third years after planting. Mature yields are not reached until the third year after planting. The target yields are shown in Table 6.3, below.

1

Throughout the world, subsoil drainage systems are a requirement for sustainable irrigation using saline water applied to the surface or in the root zone.

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• • •

• •

Existing planting machinery for sugar cane and/or other crops must be modified, tested and commissioned for A. donax. Existing forage harvesting equipment needs to be evaluated to select the most appropriate options. Costs are “full” costs, i.e. inclusive of administration, machinery depreciation and infrastructure overheads. The 450 to 500 mm average annual rainfall in the area, falling predominantly in the April-October period, is likely to be sufficient to flush accumulated salts in the soil profile of non-irrigated systems at a rate that will maintain the A. donax in a satisfactory physiological condition to achieve the target dryland yield/hectare. A 35 year life of the stands is assumed, with an accumulated 1 % p.a. reduction in production from year 26 to year 35. The A. donax production company requires a 15% p.a. internal rate of return (IRR) on funds in use to be viable.

Table 6.1: Preliminary cost assumptions for A. donax plantations ($/ha)

Item

Cost

Comments

Land rent

150

10% p.a. of the estimated land value

Planting (dryland)

400

Yr 1 only, Stems rooting at the nodes method

Planting (irrigated)

600

Yr 1 only, Stems rooting at the nodes method

Soil amelioration

500

Yr 1only, clay spreading to overcome non-wetting

Soil preparation for planting

100

Yr 1 only

Fertiliser/tonne oven dry tops

15

N, P, K & micronutrients at inorganic prices

Fertiliser/tonne oven dry tops

3.75

Factory returns captured nutrients and yeast, free

Irrigation and drainage infrastructure

7000

Yr 1 only

Irrigation power

200

Irrigation maintenance & scheduling

300

Harvesting

50

Transport to factory (t/km)

0.20

50 km average distance to factory from crop site

Deep ripping selected areas

200

Yr 1 only

Sundries, administration & overheads

100

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Table 6.2: Preliminary industrial A. donax growing system costs/ha: summary ($)

System

Yr 1

At maturity

Dryland, fertiliser purchased

1450

750

Dryland, free nutrient return from factory

1450

525

Roots in water table, fertiliser purchased

1650

1050

Roots in water table, free nutrient return from factory

1650

750

Irrigated, fertiliser purchased

9150

1700

Irrigated, free nutrient return from factory

9150

1250

Table 6.3: Preliminary factory gate “oven dry” tops $/t to achieve 15% IRR and mature A. donax plantation yields (t/ha/year of “oven dry” tops)

System

Price

Mature Yield

Dryland, fertiliser purchased

67

15

Dryland, free nutrient return from factory

52

15

Roots in water table, fertiliser purchased

49

30

Roots in water table, free nutrient return from factory

37

30

Irrigated, fertiliser purchased

80

40

Irrigated, free nutrient return from factory

70

40

Comments Free nutrient return from the factory could be a false economy. The factory enterprise should consider a charge for these nutrients to assist with its own cash flow. Likewise dried yeast or bacteria represents a high value protein source for intensive animal industries, which may be prepared to pay for this by-product. Clearly, the most economic way to grow the crop is where it is possible for the crop roots to extract water from the shallow saline water table. However, at this point the success of this strategy is highly uncertain - future R&D would be required to validate this assumption. If production was equally divided between the three production system types, and with nutrients fully costed, the factory average gate price of oven dried A. donax would be about A$65/tonne. If factory nutrients were returned to the growing company free of charge the average price was $53/oven dry tonne. While the irrigation enterprise is an expensive operation, its consideration may be worthwhile on the basis of ensuring a reasonable continuity of supply of feedstock in dry seasons.

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The possible future addition of carbon credits at A$30/t carbon in the rhizomes 2 adds an extra 1% to the assumed internal rate of return of 15% p.a. required by the A. donax production company. B. Indicative internal rates of return for enterprises producing bioenergy and other products or paper pulp These indicative internal rates of return are based on a complex of A. donax plantations of total area of 20,000 ha within 50 -100 km of a proposed factory which would produce 0.5 M t dry top growth/year (1 M t fresh weight), at an average factory gate price of $60 per tonne dry weight. Electricity and biochar generation An example of the use of a large scale A. donax plantation is to produce electricity with or without biochar (depending on profitability of the relative end products). 0.5 M t dry top growth/year will produce 65 MW/hr, plus biochar (Downie 2009). Based on “Best Energies Australia NSW” costs and returns for an electricity and biochar generation slow pyrolysis factory, preliminary internal rate of return (IRR) calculations, ex SARDI, suggest an IRR on funds employed of 8% p.a. at $100/MWh and $120/t of biochar. This IRR is a preliminary, mid best estimate figure only. The factory capital costs are estimated to be $200M, amortised over 20 years. Clearly, at the prices and assumptions used electricity plus biochar generation does not constitute at attractive investment proposition using an IRR of 15% p.a. as a minimum, acceptable benchmark for private enterprise investment. However, the economics of electricity generation may improve if other combustion processes are used and/or the price of electricity significantly increases. Bioethanol and lignin production 0.5 M t dry top growth/year will produce a minimum estimated 1.5 M litres of ethanol plus 50,000 t of lignin per annum (source estimates). Based on costings from a firm interested in growing A. donax for ethanol and lignin production (modified for local conditions), costs and returns for an ethanol and lignin factory, preliminary internal rate of return calculations, ex SARDI, suggest an internal rate of return (IRR) on funds employed of 22% p.a. at 60 c/L of bioethanol and lignin at A$50/t. This IRR is a preliminary, mid best estimate figure only. The bioethanol factory capital costs are estimated to be $275M, amortised over 20 years. This preliminary analysis meets the minimum IRR benchmark requirement (15% p.a.). Current indications are that in the medium-long term petrol prices will increase at a rate greater than the consumer price index (The Economist, 2009), further indicating a sound investment. Also the yield of ethanol from each dry tonne of biomass is continuing to increase as improved technology becomes available (The Economist, 2008).

2

Assumptions: Carbon payments only apply until the roots and rhizomes (root-like underground storage organs) reach dynamic equilibrium at the end of year 3. Further credits may apply if R&D shows significant long-term carbon storage in the roots. To date only rhizomes have been assessed.

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Integrated bioethanol, lignin, electricity and biochar generation The integrated system proposed consists of a bioethanol factory, as above, then using the 65% of original biomass feedstock which is waste as feedstock for a pyrolysis factory as above, which then generates electricity and biochar. This option provides an internal rate of return of 21% p.a., based on the assumptions used (adapted from those used in the examples above). Therefore it does not appear to offer benefits as a private enterprise investment compared to bioethanol plus lignin alone. The reason for the reduced IRR compare to ethanol and lignin production alone is the large start-up plant costs for an electricity plus biochar factory, producing a relatively poor return. Hence the daily 60% waste biomass residues from the original A. donax feedstock ferments to bioethanol can be returned to plantations to partially supply the nutrient requirements of these plantations. Paper pulp generation 0.5 M t dry top growth/year will produce an estimated 200,000 t of high quality paper pulp at a factory capital cost of $550MM amortised over 20 years (D Paul, Fibrecell, pers. comm.). Based on Fibrecell costs and returns for a paper pulp generation factory, preliminary internal rate of return (IRR) calculations, ex SARDI, suggest an IRR on funds employed of 18% p.a. at $1100/t paper pulp as a central estimate price. Summary of IRR calculations and comments Table 6.4 summarises the IRR findings for the options discussed above. The results show that the IRR is highly sensitive to the price of the main product from the conversion factory. Table 6.4: IRR results for conversion factories using A. donax feedstock sited in the South East of South Australia (central price estimates shown first in each series).

Product

Product price

Capital cost

IRR

(main product in bold)

($)

($ M)

(%)

Electricity & biochar

100/KWhr, 120/t

200

8

Electricity & biochar

120/KWhr, 120/t

200

14

Electricity & biochar

80/KWhr, 120/t

200

0

Bioethanol & lignin

0.6/L, 50/t

275

22

Bioethanol & lignin

0.8/L, 50/t

275

33

Bioethanol & lignin

0.4/L, 50/t

275

9

Bioethanol & lignin &

0.6/L, 50/t &

275 &

Electricity & biochar

100/KWhr, 120/t

160

Paper pulp

1100/t

550

18

Paper pulp

1400/t

550

28

Paper pulp

800/t

550

5

21

A large complex of A. donax plantations, managed by a growing company with a conversion factory situated in the upper South-East of SA shows potential to offer South Australia a new industry to produce both bioethanol and lignin or paper pulp, provided 3 years of near market agronomy R&D and upscaling is funded and conducted. Preliminary estimates indicate an internal rate of return on

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funds employed of 22 % p.a. for the former and 18% p.a. for the latter, based on central price estimates. Electricity generation plus biochar production using a slow pyrolysis process does not appear to represent a sound private enterprise investment, based on the preliminary analyses. However, the economics of electricity generation from A. donax feedstocks may improve if other combustion processes are used. For example, electricity generation using a fast pyrolysis process that does not produce biochar as a co product is a more efficient conversion process for electricity generation alone (R. Tonkin, pers. comm.). It is expected that the commercial potential of non food, cellulosic crop feedstocks grown on marginal lands for conversion to biofuels will increase in future if the price of fossil fuels rises significantly, as is expected (The Economist 2009). Disclaimer Please note that the estimates and price predictions are based on preliminary estimates and require further corroboration with data from existing and future information sources including future R&D and private enterprise biomass conversion companies. We suggest that the central estimates could be on average within a range +/- 30 % of the figures shown.

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Implications The cost of growing A. donax in the Upper South East of South Australia, in the Meningie Downs area was assessed. Three types of production system were envisaged: dryland, conventionally flood irrigated and a ‘naturally irrigated’ through the plants roots reaching the shallow, moderately saline water table. At the average factory gate price of A$60/oven dry tonne estimated (this allows for a 15% internal rate of return to the growing company) and 500,000 oven dry tonnes supplied per year to a conversion factory, A. donax shows potential to offer South Australia a new industry to produce either bioethanol and lignin, or pulp/paper, provided 3 years of near market agronomy research and development and upscaling is funded and conducted. Preliminary estimates indicate an internal rate of return on funds employed of 22% per annum for the ethanol and lignin enterprise and 18% per annum for the pulp/paper enterprise, based on central price estimates. It is expected that the commercial potential of non-food, lignocellulosic crop feedstocks grown on marginal lands for conversion to biofuels will increase in future if the price of fossil fuels rises significantly, as is expected (The Economist 2009), and if the crops can attract carbon credits. The implications for industry in Australia are encouraging. Australia has large areas of underutilised, cheap marginal lands and saline ground waters or low quality wastewaters. Australia has a modern, technologically-driven agricultural sector that could benefit from development of new regional industries based on non-food biofuel or pulp/paper crops and carbon credits. A. donax has potential to be a good lignocellulosic feedstock, when grown in non riparian zones provided ongoing protocols are put in place to prevent any spread to riparian zones. A. donax, together with other lignocellulose feedstocks could form the basis of new biofuel and/or pulp/paper industries for Australia. Mining and food processing industries can also consider growing salt tolerant A. donax for disposal of moderately saline wastewaters on marginal lands in non riparian zones (using an integrated biosystem such as ‘serial biological concentration’) and producing lignocellulosic feedstock for biofuels or pulp/paper. Rural communities can explore the options for growing A. donax, a non-food, energy crop on underutilised land and using moderately saline water resources and benefit from job creation from new industries.

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Recommendations It is recommended that this report be used to assess baseline data on the agronomic systems, salt tolerance, weed risk management and potential biomass yields and carbon sequestration of A. donax grown for lignocellulosic feedstocks for biofuels or pulp/paper (on marginal or arable lands in dryland or irrigated biosystems). The report also provides preliminary estimates of indicative factory gate prices for A.donax, on different classes of land and internal rates of return for enterprises producing bioenergy and other products or pulp/paper in South Australia. A number of research and development gaps have been identified. •

Further work is needed to validate findings in small scale commercial plantations of A.donax of 5 hectare by 3 industrial biosystems, to upscale and demonstrate production systems developed in this report. The three proposed production systems are: dryland, roots self irrigated by the shallow water table and a saline, flood irrigation/drainage biosystem).

•

Develop pilot commercial systems of whole stem and/or rhizome plantings (based on the findings of Christou et al. 2000), with modifications to sugar cane planting and harvesting equipment to handle A. donax for large scale plantations, in non riparian zones of Australia.

•

Definition of the minimum nutrient and irrigation requirements of A. donax for target biomass yields for a range of environments. This should include assessment of wastewaters of different qualities on the survival and productivity of A. donax.

•

Plant species in Australia posing significant weed risks can be regulated through the various noxious weed Acts of the States and Territories. These are policy decisions for each government. As such it is not appropriate for this report to mandate a particular management approach. Rather, it is a guide for each State or territory to consider in determining their policy on A. donax. Each State interested in the potential cultivation of A. donax needs to develop a sound weed risk management policy (in the early stages of industry development).

•

It is desirable to obtain funds and conduct an International forum on: ‘Potential and barriers to develop A. donax and other lignocellulosic crops for biofuels or pulp/paper’. This would greatly facilitate the compilation of best practices and technologies to help establish new second generation biofuels industries.

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Appendices Appendix 1.A: Soil descriptions and meteorogical data The Henley Beach and Control profiles have brown calcareous sandy loam surfaces, which are almost certainly ‘unnatural’, as they are significantly lighter in colour than the second layer (i.e. original surface), and in the case of the Control profile, are underlain by acidic sand. They are described, but ignored for classification purposes. The surface of the Loveday profile also appears unnatural, principally on account of its colour, which is more typical of deep subsoil sands in the region. It is however included in the classification, as the second layer is definitely not a buried surface soil. Profiles are classified according to the Australian Soil Classification (ASC) (Isbell, 2002), pH estimated from Inoculo Field pH test kit. Table 1.A.1: Soil profile descriptions for A. donax sites at Barmera, South Australia.

Site Loveday Rootstock planting

Depth (cm) 0-20 20-60 60-70 70-85

Description / Classification Soft yellowish brown (10YR5/4) single grain loamy sand, pH = 5 Friable red (2.5YR4/6) massive light sandy clay loam, pH = 8 Firm red (2.5YR4/6) massive very highly calcareous sandy light clay, pH=8.5 Firm yellowish red (5YR5/8) massive very highly calcareous sandy light clay with 20-50% calcareous nodules (2- 60 mm), pH=8.5 Sodic, Supracalcic, Red Kandosol; medium, non-gravelly, sandy / clayey, moderate ‘Sodic’ assumes ESP>6 in the lower profile. ‘Moderate’ assumes calcrete at 85 cm. Henley 0-20 Friable brown (10YR5/3) massive highly calcareous light sandy loam, pH = Beach 8.5 Friable dark brown (7.5YR3/3) massive highly calcareous heavy sandy loam, Rootstock 20-40 pH=9 planting 40-70 Friable yellowish red (5YR4/6) massive highly calcareous sandy clay loam, pH=9 70-80 Friable yellowish red (5YR5/6) massive very highly calcareous sandy clay loam with 20-30% calcareous nodules (2-20 mm), pH=9.5 Ceteric, Petrocalcic, Supracalcic Calcarosol; very thick, non-gravelly, loamy / clay loamy, moderate ‘Ceteric’ assumes ESP<15 in all layers. ‘Petrocalcic’ and ‘moderate’ assume calcrete at 80 cm. Control 0-29 Soft brown (10YR5/3) single grain moderately calcareous light sandy loam, pH = 8.5 Area, 29-53 Loose dark greyish brown (10YR4/2) single grain light loamy sand, pH = 6.5 virgin 53-103 Loose pale brown (10YR6/3) single grain light loamy sand, pH = 5 land 103-120 Soft strong brown (7.5YR5/8) single grain loam sand, pH = 6 Basic, Regolithic, Brown-Orthic Tenosol; medium, non-gravelly, sandy / sandy, deep If calcrete occurs at 120 cm, ‘Regolithic’ becomes ‘Petrocalcic’

91

Table 1.A.2: Roseworthy Monthly Weather Data Year 2005

92

Jun Jul Aug Sep 17.7 15.9 17.6 18.3 7.6 6.3 6.3 6.3 101.2 31.2 60.8 53.6 54 37.2 62 78 5.4 5.2 6.8 6.8 15.8 15.1 18.8 22.4 2006 3.4 5 4 5.6 16.6 34.2 9.4 23.2 36 40.3 62 108 5.7 8.7 5 7.6 14.4 15.4 18.4 21.7 2007 4.4 5.3 5 6.4 35.4 23.4 35.8 15 30 43.4 68.2 114 5.2 8.4 8.6 5 17.2 14.6 14.6 20.6 2008 7 5.7 3.9 5.4 17.8 49.6 73.4 25.8 46.5 49.6 96 45 5.2 4.9 5.6 9 16.3 19.8 15.3 17.9 2009 7.5 6.4 6.3 6.3 50.4 59 44.6 5 36 43.4 58.9 87 4.6 5.5 6.5 5.6 Source: Peter Clement, SA Office of the Bureau of Meteorology Max. Temp. = Mean maximum air temperature (oC) (from Roseworthy weather station) Min. Temp. = Mean minimum air temperature (oC) ( " " " " ) Precip. = Total monthly precipitation (mm) ( " " " " ) Evap. = Total monthly evaporation (mm) (from Rosedale weather station) Sunshine = Total monthly hours of bright sunshine (hours) (from Nuriootpa weather station) Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine

Jan 29.8 13.2 26.2 226.3 10.1 34.1 17.3 23.8 291.4 9.6 30.7 16.4 40.2 238.7 10 32.4 13.9 0.4 291.4 11.7 33.1 14.2 0.6 306.9 12.3

Feb 27.9 12.5 14 182 9.8 29 12.5 45 187.6 10.1 34.1 16.4 1.8 238 11.2 28.9 13.2 0 223.3 9.7 32.9 15.9 0 257.6 10.7

Mar 27 10.4 9.4 167.4 9.3 29.7 13.4 10 201.5 9.4 28 13.8 36 186 8.1 34.3 16.7 8.6 244.9 9.7 27.8 12.6 9 170.5 8.1

Apr 27 11.8 15.2 165 8.9 21 10 39.4 90 6 25.1 12.2 80.8 120 8.1 23.1 9.5 29.6 123 7.3 23.6 10.6 48.2 126 7.8

May 21.9 7.5 2.8 74.4 6.8 17.4 6.5 35 49.6 4.7 20.8 10.3 19.4 62 6 20.3 8.7 47.6 65.1 7.1 18.7 8.5 25.2 55.8 5

Oct 22 8.9 111.2 127.1 8 26.2 6.2 0.4 189.1 10.2 25.3 7.6 6.8 170.5 8.6 25.2 7.5 7.4 167.4 8.8

Nov 26.6 9.6 53.6 162 9.1 28.4 10.5 3.2 222 10.2 29.8 10.6 17.6 219 10.6 26 10.8 13 198 9.1

Dec 30.3 13.4 41.6 232.5 10.4 31.1 13.5 25.4 269.7 10.5 31.7 13.3 18.4 260.4 10.2 26.4 12.5 51 210.8 8.6

Annual 23.5 9.5 520.8 1567.9 8.1 24.1 9 265.6 1747.2 8.1 24.6 10.1 330.6 1750.2 8.3 23.6 9.6 324.2 1761 8.1

Table 1.A.3: Loxton Research Centre Monthly Weather Data

Year 2005

93

Mar Apr May Jun Jul Aug Sep 27.5 27 21.2 17.1 16.1 18.8 19.8 10.6 9.6 5.7 6 4.2 4.9 7.4 9.4 10.4 0.6 69 23.2 18.6 40.8 195.3 162 89.9 57 49.6 108.5 114 8 7.6 10 9.7 5.8 6.2 8.1 21.5 17.4 19.1 29.9 15.5 15.6 23 2006 1.1 12.7 7.5 5.1 4.1 3.1 6.1 9.4 7.4 36.4 41.4 3 29.4 5.2 232.5 114 71.3 51 62 99.2 174 10.3 7.7 6.5 6.7 6.1 9 9.6 21.4 19.9 28.2 25.6 14.8 16.2 22.7 2007 13.5 9.6 8.6 2.9 3.1 3.8 6.2 2.5 6.8 28.8 34.6 50.1 27 2.6 217 138 86.8 51 65.1 117.8 171 8.6 8.7 7.6 6.2 6.5 9.6 9.6 31.8 23.4 20.2 17.3 15.5 15.8 22.2 2008 12.3 7.1 5.7 5.6 3.9 4.2 5.2 9 34 27.2 5.8 0.4 20.2 26.8 248 129 68.2 54 65.1 74.4 153 10.1 8.1 7.7 5.4 6.1 6.7 8.9 28.6 23.9 19.5 16.8 16.6 20.3 21.8 2009 12.3 8.1 7.8 5.1 5.1 6 7.9 1.5 24.4 4.6 21 25.4 15.6 38.8 201.5 129 74.4 45 62 111.6 156 8.5 9 6.6 5.6 5.8 7 8.4 Source: Peter Clement, SA Office of the Bureau of Meteorology Max. Temp. = Mean maximum air temperature (oC) Min. Temp. = Mean minimum air temperature (oC) Precip. = Total monthly precipitation (mm) Evap. = Total monthly evaporation (mm) Sunshine = Total monthly hours of bright sunshine (hours) Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine Max. Temp. Min. Temp. Precip. Evap. Sunshine

Jan 31 14.5 43.8 291.4 9.9 35 18.4 6.4 347.2 9.8 31.6 16.3 59.6 297.6 9.4 33.3 15.9 11.6 328.6 10.2 34.5 13.9 0.2 337.9 12.3

Feb 28.9 12.9 10.2 221.2 9.8 30.4 13.8 7.6 257.6 10.7 34.2 16 3.8 268.8 10.7 29.5 13.5 1.2 263.9 10.3 33.1 14.9 0 288.4 11.6

Oct 23.4 10 71.6 164.3 8.3 25.9 6.7 0.2 238.7 10.7 25.5 8.1 12.2 223.2 9.3 26.6 8.8 4.6 210.8 9.3

Nov 27.6 11.7 24.4 237 9.9 29.1 11 10.6 261 9.7 30.4 13 35.4 246 9.8 26.6 11.6 26.9 228 8.8

Dec 31.4 13.4 11.6 306.9 10.2 30.3 12 8.8 306.9 10.3 31.2 13.8 14.1 291.4 9.7 28.1 12.7 31.6 263.5 9.2

Ann 24.2 9.2 333.6 1997.1 8.6 24.4 8.5 165.8 2215.4 8.9 25.1 9.6 277.5 2173.7 8.8 24.2 8.9 199.3 2086.5 8.4

Appendix 1.B: Batch Pyrolysis Trial of A. donax by Pacific Pyrolysis

Prepared for SARDI

Prepared by:

Environmental and Informational Sciences

Approved by:

Adriana Downie

Issue Date:

23 October 2009

94

Executive Summary A sample of A. donax supplied to BEST Energies was pyrolysed in an 18L batch pyrolyser. Samples of the feedstock and biochar product then underwent proximate and ultimate analysis via a third party laboratory to determine the fundamental suitability of A. donax as feedstock for commercial pyrolysis applications. From the results it was found: ■

Provided the A. donax underwent suitable preparation (comminution) it should not pose any handling problems.

■

The A. donax gave a biochar yield of 30.7% by mass on a dry basis, when pyrolysed at 550ºC with steam activation.

■

This low biochar yield is associated with the high volatile content (74.9%) of the feed material.

■

The high volatile content results in a high production of syngas and thus energy.

■

The proximate and ultimate analysis results showed that the product biochar has a high percentage of fixed carbon and is likely to be stable and provide long term carbon sequestration.

■

The stable, high carbon biochar produced is likely to be a valuable soil amendment product and also contains potassium, iron, nitrogen, calcium and other compounds with nutrient value.

■

An energy balance showed that 52% of the energy in the feedstock will be transferred to the syngas, with each dry tonne of A. donax producing 9.76GJ of syngas energy.

From the results it was concluded, that A. donax is a suitable material for commercial pyrolysis, and it is recommended that further pilot scale testing be undertaken to allow more detailed information to be gathered for design of a full scale plant.

95

Introduction SARDI (South Australian Research and Development Institute) has engaged BEST Energies Australia’s Pty Ltd (BEST) to undertake a small scale batch pyrolysis trial on a sample of A. donax (giant reed) to assess the suitability of this material as a feedstock for pyrolysis. The methodology used for the batch pyrolysis trial was as follows: ■

Assessing the A. donax sample for the fundamental suitability as feedstock for the BEST Energies Slow Pyrolysis Process.

■

Pyrolysing the sample provided in an 18L batch pyrolyser the produce biochar and syngas.

■

Analysis of the A. donax sample and biochar product via a third party laboratory to determine the chemical suitability as a pyrolysis feedstock and the mass and energy balance across the process.

■

Calculating basic process data to determine expected energy and biochar yields.

■

Providing a small sample of the product biochar for product development purposes.

■

A brief report (in electronic form) detailing the results of the above.

Feedstock Suitability The A. donax sample provided to BEST energies was extremely dry, with a low moisture content of 7%, making it a good candidate for thermal conversion technologies. The moisture content was determined by mass difference during drying at 110ºC. Biomass moisture contents below 10% are unusual, and the sample may have been pre-dried before supply to BEST. Provided the moisture content of the feedstock is below approximately 20%, there is enough heat available from operation of the pyrolysis process to completely dry the incoming biomass without additional input of energy, which increases the net energy yield from the pyrolysis process. In terms of material handling, the A. donax sample consisted of large fibrous pieces that would be difficult to convey using standard materials handing equipment such as screw conveyors. To make the material more suitable, comminuting would be necessary. For fibrous materials a cutting action is required in order to prevent the formation of fibrous clumps that are difficult to convey.

96

Batch Pyrolysis Trial Sample Preparation Approximately 10L of the A. donax received was oven dried at 110°C for 24 hours until bone dry (no physical moisture remaining). The initial and final weights were recorded to determine the moisture content and biochar yield. Batch Pyrolysis Processing Approximately 3kg of dry A. donax was processed in a stirred batch pyrolysis kiln heated by gas burners. The sample was heated to 550°C at a rate of 5-10°C per minute, while constantly stirring. An automatic gas-controller was used to operate the burners, to ensure a constant heating rate. The material was then held at approximately 550°C for a period of 40 minutes. A photograph of the batch pyrolysis rig is shown in Figure 1.B.1. The gases from the pyrolysis process were released through a chimney into a simple flare, and combusted. The chimney was kept capped until positive pressure (around 200°C) was obtained inside the kiln, to help prevent air entering and causing oxidation. When 550ºC was reached inside the kiln, a small flow of steam was introduced into the kiln to activate the biochar. This process produces some additional syngas and also greatly increases the surface area of the biochar while removing any residual tars. Once the required residence time had passed, the kiln was purged with nitrogen until the kiln temperature dropped below 200°C. This inert environment prevents oxidation. Once cooled, the product biochar was collected by removing the front refractory lined flange and weighed. The recorded process data from the run is graphed in Figure 1.B.2. The data corresponds to readings taken from thermocouples placed at key locations within the test rig.

Figure 1.B.1: Batch pyrolysis test rig.

97

Batch Pyrolysis Data: 9th September 2008 700

600

Temperature (ºC)

500

400

300

200

100

0 7:04

7:14

7:24

7:34

7:44

7:54

8:04

8:14

8:24

8:34

8:44

8:54

9:04

9:14

9:24

9:34

9:44

Time Kiln Average

Kiln Bottom

Kiln Front

Steam to Kiln

Syngas Exit

Figure 1.B.2: Recorded process data from batch pyrolysis run.

Batch Pyrolysis Results and Discussion Pyrolysis Results Due the size of the A. donax material, handling and processing was hindered. The production of syngas was very good, however during pyrolysis a large amount of fine dust was created. An overall biochar yield of 30.7% was achieved based on the feedstock dry weight. A summary of the batch pyrolysis results is reported in Table 1.B.1.

98

Table 1.B.1: Summary of batch pyrolysis trial results.

Sample Handling

Pyrolysis Results

Date:

9th September

Biochar Activated:

Steam

Test temperature:

550°c

Oven Dried:

Yes

Product:

A. donax

Raw Dry Weight (g):

2300

Moisture Content:

7.0%

Biochar Weight (g):

707

Residence Time:

40 minutes

Biochar Yield:

30.7%

Heating Rate:

5-10°c per minute

Feed Method:

Cold

Stirring Rate:

Constant @ 6hz

Biochar Analysis Samples of both A. donax, and the resulting biochar were sent to Bureau Veritas International Trade Australia Pty Ltd for proximate, ultimate and ash constituent analysis. Proximate analysis determines the content of, moisture, ash, volatile matter, fixed carbon, and also the calorific value (heating value) of sample. Ultimate analysis determines the basic elemental composition. The ash constituent analysis determines common elemental composition of the ash fraction remaining after combustion. The complete report from Bureau Veritas International Trade Australia (ITA) can be found in Tables 1.B.3 and 1.B.4 at the end of this appendix.

Proximate Analysis Figure 1.B.3 shows the result of proximate analysis expressed as a dry basis percentage of the feedstock or biochar. Figure 1.B.4 shows the gross calorific value of the feedstock and biochar expressed on a dry basis. The proximate analysis results can be used to evaluate the energy balance during the pyrolysis process. During pyrolysis at 550 °C, approximately 80-95% of volatile matter is removed from the feed, leaving behind a biochar composed mainly of fixed carbon and ash. The ash is primarily composed of the inorganic components in the original feedstock.

99

Feedstocks with a higher volatile fraction produce more syngas during the pyrolysis process and a lower yield of biochar. Feedstocks with higher ash content, and/or lower volatile content, tend to produce less syngas and a higher biochar yield. Feedstocks with very high ash contents are more energy intensive to pyrolise due to the need to heat up the inert ash. The proximate analysis results show A. donax has a high volatile content (75%), and relatively high ash content (4.8%). For comparison, woods can have ash contents less than 1%. The high volatile content corresponds to the good production of syngas observed during the pyrolysis trials. This will mean that pyrolysis of A. donax will produce a large quantity of quality syngas for energy production, but a lower biochar yield. Removal of the volatile fraction in the feedstock increases the concentration of the ash and fixed carbon remaining in the biochar. This has the effect of greatly increasing the calorific value (energy content) of the biochar over the original feedstock, due to the volatile fraction having a lower energy content. If energy production is a priority over biochar production, in the BEST Energies pyrolysis system the biochar produced can be gasified in a secondary reactor to remove some or all of the remaining fixed carbon, to leave behind a very high ash biochar with a low energy value, while producing additional syngas for energy production. The biochar produced from A. donax contains a high percentage of fixed carbon (73.6%), indicating that it would be suitable for gasification if additional energy was required.

Proximate Analysis 80%

70%

60%

50% Ash (at 575º) Volatile Matter Fixed Carbon

40%

30%

20%

10%

0% Feedstock

Char

Figure 1.B.3: Proximate analysis results.

100

Gross Calorific Value 35

30

25

MJ/kg

20

15

10

5

0 Feedstock

Char

Figure 1.B.4: Gross calorific value results.

Ultimate Analysis The ultimate analysis gives an indication of both the carbon balance and the nature of the organic compounds constituting the material. The results of the ultimate analysis are shown in, Figure 1.B.5 and are expressed as a dry basis percentage of the feedstock or biochar. The results show that there has been a large reduction in the ratios of hydrogen and oxygen to carbon, which is an important indicator as to the increasing aromatic nature and stability of the biochar in soil. Biochar stability is important to ensure long term carbon sequestration. The results also show that some of the nitrogen in the original feedstock is concentrated into the biochar, which will give additional benefits if the biochar is used as a soil amendment.

101

Ultimate Analysis 90% 80% 70% 60% 50% Feedstock Char

40% 30% 20% 10% 0% Carbon

Hydrogen

Nitrogen

Sulfur

Oxygen

Figure 1.B.5: Ultimate analysis results.

Ash Constituents The ash constituent analysis provides a good indication of the inorganic components of the feedstock. Figure 1.B.6 shows the results of the ash constituent analysis for the ash derived from the A. donax material. The results are expressed as a percentage of the mass of ash within the A. donax. With the exception of sulphur which is volatile, during pyrolysis the constituents of the ash in the feedstock are retained in the biochar ash in the same proportions. Due to the greater amount ash in the biochar, the constituents will be in greater concentration than in the feedstock. Several of the inorganic compounds found are of significant nutrient value. Inorganics such as phosphorous, potassium, calcium, soluble silicon, and iron have agricultural value. The ash from the A. donax contains high concentration of several of these minerals.

102

Feedstock Ash Constituent Analysis 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 5%

Si lic on

Al as um Si in O iu 2 m as Al 2O Iro 3 n as Fe C 2O al ci 3 um M as ag C ne aO si um as So M gO di um as Po N a2 ta ss O iu m as Ti K2 ta O ni um M an as ga Ti ne O se 2 as Ph M os n3 ph O or 4 us as P2 O Su 5 lfu ra s St SO ro nt 3 iu m as Sr Ba O riu m as Ba O Zi nc Va as na Zn di O um as V2 O 5

0%

Figure 1.B.6: Feedstock ash constituent results.

Mass and Energy Balance Using the results obtained from the proximate analysis of both the feedstock and biochar, Table 1.B. outlines a basic mass and energy balance. The balance shows that 52.2% of the energy in the feedstock is transferred into the syngas, which is high value owing to the large volatile content of the feedstock. Thus each dry tonne of A. donax will produce 9.76GJ of energy. If greater energy production is required (more syngas), the biochar could be partially or completely gasified. For a standard 4 tonne per hour (dry basis) pyrolysis plant, syngas with an energy value of 39GJ/hr or 10.8MW would be produced. Typically 30-35% of this syngas energy is required to operate the pyrolysis plant, with the remainder available for thermal or electrical power generation.

103

Table 1.B.2: Mass and energy balance. Calculation Basis: Char Yield: Calorific Value (MJ/kg): Mass (tonne): Energy Value (MJ): Energy to Syngas:

1.00 tonne feedstock 30.7%

Feed

18.69 1.00 18,690

Char

29.10 0.307 8,934

9,756 MJ 52.2% of feedstock energy

Conclusions and Recommendations The batch pyrolysis tests have shown that giant A. donax is a suitable material for slow pyrolysis; however, attention would need to be paid to preposing of the material due to its fibrous nature. It will produce a high energy yield in addition to a stable biochar with a high proportion of fixed carbon. Additionally the retention of nitrogen in the biochar and the constituents of the ash will result in the biochar providing some nutrient value. Due to the promising batch pyrolysis test results, it is recommended that more extensive pilot scale testing be undertaken by processing several tonnes of A. donax in the BEST Energies Pilot Scale Slow Pyrolysis Plant. This will enable detailed process information to be collected for the evaluation and design of a full scale plant. It will also provide a substantial quantity of biochar for agricultural field trials.

104

Table 1.B.3: Proximate and ultimate analysis results from ITA for A. donax feedstock

Giant Reed Sample ITA sample number

M57647

Topsize received (mm) Mass received Analysis Basis

+50

(g) (ad)

101.4 (db)

(daf)

Proximate Analysis Air dried moisture Ash

o

(at 575 )

Volatile matter Fixed carbon Gross calorific value

**

(%)

7.0

(%)

4.5

4.8

(%)

69.7

74.9

(%)

18.8

20.3

(MJ/kg)

17.38

18.69

19.64

(kcal/kg)

4152

4464

4690

**Note: Due to the matrix of the sample we were unable to get the result within repeatability and have reported the average of 4 results. Ultimate Analysis Carbon

(%)

44.2

47.5

49.9

Hydrogen

(%)

5.40

5.81

6.10

Nitrogen

(%)

0.66

0.71

0.75

Total Sulfur

(%)

0.10

0.11

Oxygen (by Diff)

(%)

38.1

41.0

(ar) = ‘as received” basis, (ad) = ‘air dried” basis, (db) = “dry basis” Ash Constituent Analysis

(%db)

Silicon

as

SiO2

52.2

Aluminium

as

AL2O3

3.2

Iron

as

Fe2O3

7.4

Calcium

as

CaO

1.9

Magnesium

as

MgO

2.2

Sodium

as

Na2O

0.10

Potassium

as

K2O

26.0

Titanium

as

ToO2

0.07

Manganese

as

Mn3O4

0.14

Phosphorus

as

P2O5

1.3

Sulfur

as

SO3

4.3

Strontium

as

SrO

0.04

Barium

as

BaO

<0.01

Zinc

as

ZnO

0.05

Vanadium

as

V2O5

0.01

‘The results of an ash analysis do not necessarily total 100%” Analysed at ITA Newcastle in accordance with Australian Standard Methods

105

Table 1.B.4: Proximate and ultimate analysis results from ITA for A. donax biochar

SARDI CHAR CCI Sample Number Topsize Received

M58456 (mm)

5

(g)

12

Mass Received

(ad)

Analysis Basis

(db)

(daf)

Proximate Analysis (%)

6.0

o

(%)

10.7

11.4

Volatile Matter

(%)

14.1

15

Fixed Carbon

(%)

69.2

73.6

(MJ/kg)

27.35

29.10

32.83

(kcal/kg

6523

6950

7842

Air Dried Moisture Ash

(at 575 C)

Gross Calorific Value**

**Note: Due to the matrix of the sample we were unable to get the result within repeatability and have reported the average of 3 results (no sample left) Ultimate Analysis Carbon

(%)

72.1

76.7

86.6

Hydrogen

(%)

2.45

2.61

2.94

Nitrogen

(%)

1.13

1.20

1.36

Total Sulfur

(%)

0.28

0.30

Oxygen (by Diff)

(%)

7.3

7.8

(ar) = ‘as received” basis, (ad) = ‘air dried” basis, (db) = “dry basis”

Analysed at Bureau Veritas International Trade Australia, Newcastle in accordance with Australian Standard Methods AS1038.5, AS 1038.3, AS1038.6.3.3, AS1038.6.4 and AS4264.1

106

Appendix 2.A: Water, plant and soil chemical analyses Table 2.A.1: Irrigation water composition (salinity (EC) and nutrients) in holding lagoon, ab Barmera, prior to application to Adx from June 2006 to July 2007.

Ammonia

Sulphate

COD c

EC

mg N/L

mg/L

mg/L

µS/cm

dS/m

mg N/L

6/6/06

<1.0

<0.5

780

1800

1.8

<0.5

8.5

6/7/06

na

na

na

3200

3.2

<0.5

8.7

8/8/06

4.3

2.8

330

3100

3.1

<0.5

na

5/9/06

4.8

4.7

340

2800

2.8

<0.5

8.7

5/10/06

5.6

8.4

350

3000

3.0

<0.5

8.8

16/10/06

na

na

na

2500

2.5

na

na

7/11/06

<1.0

6.4

580

3000

3.0

<0.5

9.6

5/12/06

na

na

na

4800

4.8

na

9.3

9/1/07

4.4

10.0

850

7000

7.0

<0.5

9.4

6/2/07

11.0

15.0

2200

9500

9.5

<0.5

9.6

6/3/07

12.0

28.0

3500

18500

18.5

<0.5

9.9

30/4/07

5.3

12.0

1200

7400

7.4

<0.5

9.6

5/6/07

4.1

3.9

930

4780

4.8

<0.5

9.4

3/7/07

1.2

<0.5

680

3810

3.8

<0.5

9.5

Date Sample Taken

EC Nitrate+Nitrite

a

AMDEL standard analytical procedures, data supplied by Hardy Wine Company.

b

180 mg/L Chloride at 5/12/06 and 150 mg/L TOC at 6/7/06.

c

COD is chemical oxygen demand (oxygen required to oxidise all compounds in water).

107

pH

Table 2.A.2: Irrigation water composition (salinity and nutrients) in holding lagoon, Barmera, at a 7 sampling dates from September 2006 to May 2007 .

Measure

Sampling date 19/9/06 16/10/06b

21/12/06

30/1/07

26/2/07

18/4/07

7/5/07

8.69

9.10

9.49

9.36

9.69

9.92

9.48

na

2.5

5.8

9.3

8.5

18.7

7.0

<0.1

na

<0.1

<0.1

<0.1

<0.1

<0.1

Cl- (mg/L)

137

na

247

442

681

925

317

Ca (mg/L)

14

34

4

6

4

7

5

K (mg/L)

709

821

1290

2352

3790

5530

1750

Mg (mg/L)

112

17

26

38

43

32

18

Na (mg/L)

251

314

483

870

1350

1890

615

5

4

10

29

23

75

17

Al (mg/L)

<0.5

0.5

<0.5

<0.5

<0.5

<0.5

<0.5

B (mg/L)

0.91

1.10

1.78

2.86

4.47

5.04

1.92

Cu (mg/L)

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

Fe (mg/L)

<0.5

<0.05

<0.5

<0.5

<0.5

<0.5

<0.5

Mn (mg/L)

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

P (mg/L)

8.77

14.0

14.55

23.11

13.58

18.07

15.57

Si (mg/L)

3.17

5.50

10.12

11.50

27.09

10.89

9.01

Sr (mg/L)

<1

0.4

<1

<1

<1

0.7

<1

Zn (mg/L)

<0.2

<0.2

<0.2

<0.2

<0.2

0.07

<0.2

pH ECw (dS/m) NO3 –N

S (mg/L)

a

b

CSIRO, Land and Water, Analytical Services, Waite Precinct, (standard procedures). NPOC value was 61.3 mg/L and Total N was 23.7 mg/L.

108

Table 2.A.3: Irrigation water composition (salinity (EC) and nutrients) in the holding lagoon, ab Barmera, prior to application to Adx .

Date of sampling

P

K

COD

BOD

EC

mg/L

mg/L

mg/L

mg/L

dS/m

pH

9.5 3.5 3470 640 0.5 na 7/08/2007 9.6 3.2 3190 700 <0.5 na 4/09/2007 9.4 4.0 3990 480 0.6 na 3/10/2007 9.8 4.8 4750 700 2.3 na 6/11/2007 9.8 5.7 5680 810 1.5 na 4/12/2007 4200 1.4 4.6 190 5800 9.9 7/01/2008 8000 1.3 8.5 11000 12.0 200 21/01/2008 9400 1.5 4.1 10.2 916 4700 4/02/2008 14000 2.1 3.7 19.4 620 11000 19/02/2008 3.7 12000 2.5 26.5 800 14000 3/03/2008 3.7 9000 2.2 38.5 710 19000 17/03/2008 4.1 11000 2.8 24.2 910 11000 1/04/2008 4.7 12000 3.1 20.8 1200 11000 15/04/2008 4.6 7000 2.5 19.5 770 13000 28/04/2008 9000 3.4 4.8 26.3 140 14000 5/05/2008 4900 2.5 6.4 16.5 730 6200 12/05/2008 100 2.4 8.4 2.2 520 330 3/06/2008 5300 1.2 6.7 3.0 200 1300 7/07/2008 6000 1.8 4.8 16.2 390 5100 4/08/2008 2700 1.7 6.3 6.7 310 2700 1/09/2008 1.6 5.5 2700 14.1 290 4500 7/10/2008 1.5 5.0 4400 17.3 270 4700 3/11/2008 na 6.8 2400 250 5.5 3600 1/12/2008 1.3 4.9 1900 12.7 180 5/01/2009 1.4 4.7 3800 11.0 210 4800 19/01/2009 2.2 4.0 11000 24.1 600 3/02/2009 1.9 4.2 20.2 780 9400 17/02/2009 2.3 4.8 11000 28.7 690 3/03/2009 2.6 4.8 9000 30.3 740 17/03/2009 4.6 2.5 8800 24.7 720 31/03/2009 4.6 2.2 4400 25.5 780 7/04/2009 4.5 2.2 10000 26.2 620 21/04/2009 BOD is Biological Oxygen Demand COD is Chemical Oxygen Demand a AMDEL standard analytical procedures, data from Constellation Wines Australia (Dr L. Low) b 180 mg/L Chloride at 5/12/06 and 150 mg/L TOC at 6/7/06. AMDEL standard analytical procedures, data from Constellation Wines Australia (Dr L. Low)

109

Table 2.A.4: Irrigation water composition (salinity and nutrients) in holding lagoon, Barmera, at a 9 sampling dates from January 2008 to April 2009 .

Chemical

Sampling date 2008 24/01

2009 14/03

pH

2/04

29/04

4/07

6/01

11/03

23/04

23/4

4.22

5.44

4.16

4.3

4.7

4.6

4.6

ECw (dS/m)

14.51

2.75

2.49

4.45

2.39

1.65

1.46

4.09

1.98

NO3 –N

<0.1

<0.1

<0.1

0.1

<0.1

<0.1

<0.1

<0.1

0.2

Cl- (mg/L)

na

na

na

na

na

na

na

na

Ca (mg/L)

11

46

35

60

32

30

21

48

49

K (mg/L)

3840

436

553

665

486

153

229

183

203

Mg (mg/L)

34

17

18

33

14

18

11

979

13

Na (mg/L)

1406

144

111

155

222

184

65

64

64

S (mg/L)

20

8.8

13

18

14

13

7

36

11

Al (mg/L)

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

B (mg/L)

5

<1

<1

<1

<1

<1

<1

1.6

<1

Cu (mg/L)

<0.5

<0.5

0.19

0.20

<0.5

<0.5

<0.5

<0.5

<0.5

Fe (mg/L)

<1

<1

<1

<1

<1

<1

<1

1.3

<1

Mn (mg/L)

<0.5

0.7

<0.5

<0.5

<0.5

<0.5

<0.5

1.23

<0.5

P (mg/L)

33

21

19

9.6

14

17

10

32

6.2

Si (mg/L)

18

2.4

2.4

2.4

1.5

4.6

2.3

18

3.4

Sr (mg/L)

5.5

5.6

2.5

3.2

4.1

1.8

2.3

4.5

2.9

Zn (mg/L)

<0.5

3.3

1.12

<0.5

<0.5

0.76

0.53

4.49

<0.5

a

b

CSIRO, Land and Water, Analytical Services, Waite Precinct, (standard procedures). NPOC value was 61.3 mg/L and Total N was 23.7 mg/L.

na = not available

110

Table 2.A.5: Irrigation water composition (nutrients and metals in mg/L) applied in 2006 at Roseworthy.

Nutrient/

Established planting

New planting

Metal1

February

June

February

June

NH4-N

1.7

0.1

7.2

0.2

NO3-N

<0.02

0.1

<0.02

13

Total N

8

6

16

21

P

0.6

1.1

3.9

13.0

K

122

16

5

109

Na

169

183

132

141

Ca

27

24

45

59

Mg

16

21

26

28

Cl

271

241

312

226

B

0.4

0.4

0.3

0.3

1

Iron, manganese, zinc and copper were below limits of detection.

111

Table 2.A.6: Average meso-nutrient concentrations of A. donax organs at Barmera for 3 annual clearfell harvests. Standard error of the mean is shown in parentheses.

Treatment

S

Ca

Mg

Fe

(%)

(%)

(%)

(%)

16/05/2007 20/08/2008 22/04/2009

0.48 (0.07) 0.31 (0.03) 0.77 (0.11)

16/05/2007 20/08/2008 22/04/2009

0.46 (0.07) 0.33 (0.02) 0.69 (0.04)

16/05/2007 20/08/2008 22/04/2009

0.10 (0.02) 0.08 (0.001) 0.14 (0.03)

16/05/2007 20/08/2008 22/04/2009

0.10 (0.02) 0.10 (0.01) 0.25 (0.04)

16/05/2007 20/08/2008 22/04/2009

0.29 (0.04) 0.29 (0.01) 0.33 (0.03)

16/05/2007 20/08/2008 22/04/2009

0.21 (0.003) 0.33 (0.01) 0.29 (0.01)

Leaf Loveday 0.49 (0.11) 0.19 (0.02) 0.41 (0.06) 0.14 (0.01) 0.78 (0.24) 0.29 (0.05) Henley Beach 0.41 (0.12) 0.17 (0.06) 0.13 (0.02) 0.11 (0.01) 0.98 (0.13) 0.25 (0.01) Stem Loveday 0.027 (0.008) 0.040 (0.004) 0.044 (0.007) 0.041 (0.008) 0.096 (0.026) 0.075 (0.017) Henley Beach 0.027 (0.008) 0.040 (0.004) 0.044 (0.010) 0.029 (0.002) 0.146 (0.010) 0.089 (0.003) Rhizome Loveday 0.068 (0.015) 0.087 (0.005) 0.072 (0.010) 0.097 (0.017) 0.178 (0.054) 0.114 (0.010) Henley Beach 0.046 (0.010) 0.061 (0.003) 0.079 (0.007) 0.066 (0.004) 0.219 (0.122) 0.084 (0.007)

112

0.016 (0.003) 0.013 (0.001) 0.026 (0.002) 0.013 (0.001) 0.013 (0.003) 0.021 (0.001)

0.003 (0.0002) 0.002 (0.001) 0.007 (0.001) 0.003 (0.0003 0.003 (0.001) 0.005 (0.0003)

0.023 (0.003) 0.017 (0.002) 0.059 (0.027) 0.025 (0.005) 0.029 (0.009) 0.103 (0.051)

Table 2.A.7: Average meso-nutrient uptake of Adx organs for 3 annual clearfell harvests at Barmera. Standard error of the mean is shown in parentheses.

Treatment

S (kg/ha) Leaf Loveday 16/05/2007 47 (15) 20/08/2008 2 (1) 22/04/2009 45 (7) 16/05/2007 20/08/2008 22/04/2009

50 (21) 1 (1) 23 (5)

16/05/2007 20/08/2008 22/04/2009

35 (4) 27 (10) 30 (1)

16/05/2007 20/08/2008 22/04/2009

22 (9) 13 (2) 19 (2)

16/05/2007 20/08/2008 22/04/2009

82 (7) 29 (11) 76 (7)

16/05/2007 20/08/2008 22/04/2009

72 (12) 13 (2) 36 (1)

16/05/2007 20/08/2008 22/04/2009

80 (25) 119 (18) 151 (42)

16/05/2007 20/08/2008 22/04/2009

35 (17) 33 (3) 25 (0.3)

Ca (kg/ha)

Mg (kg/ha)

50 (18) 18.8 (5.2) 3 (1) 1.0 (0.4) 44 (10) 16.9 (2.9) Henley Beach 43 (21) 20.7 (10.2) 0.5 (0.4) 0.3 (0.2) 31 (2) 8.3 (1.4) Stem Loveday 9 (2) 14.1 (1.1) 18 (9) 16.9 (9.4) 20 (3) 15.7 (2.0) Henley Beach 7 (3) 10.5 (6.2) 5 (1) 3.6 (0.7) 11 (2) 6.6 (0.5) Tops Loveday 60 (12) 32.9 (2.6) 20 (11) 17.9 (9.8) 63 (12) 32.6 (4.9) Henley Beach 50 (13) 31.2 (5.8) 5 (1) 3.6 (0.7) 13.9 (0.1) 42 (3) Rhizomes Loveday 20 (8) 23.6 (6.2) 31 (8) 42.5 (14.3) 75 (18) 53.2 (16.6) Henley Beach 7 (3) 10.3 (5.3) 8 (0.3) 6.6 (0.7) 19 (10) 7.3 (0.5)

113

Fe (kg/ha)

1.33 (0.20) 0.10 (0.04) 1.56 (0.18) 1.52 (0.70) 0.03 (0.03) 0.66 (0.07)

0.93 (0.01) 0.91 (0.62) 1.68 (0.67) 1.12 (0.50) 0.32 (0.08) 0.36 (0.02)

2.25 (0.10) 1.01 (0.70) 3.24 (0.75) 2.65 (0.40) 0.32 (0.10) 0.95 (0.01)

6.06 (1.4) 6.60 (0.93) 22.12 (6.05) 3.59 (1.70) 2.77 (0.83) 8.94 (4.34)

Table 2.A.8: Average micro-nutrient concentrations for 3 annual clearfell harvests at Barmera. Standard error of the mean is shown in parentheses.

Treatment

Cu mg/kg

Zn mg/kg Leaf

Mn

B

Mo

mg/kg

mg/kg

mg/kg

16/05/2007

Loveday 4.7 (0.3)

9.2 (1.9)

244 (58)

21.5 (3.2)

<0.8 (na)

20/08/2008 22/04/2009

3.4 (0.1) 6.0 (0.7)

15.6 (1.1) 17.5 (3.9)

104 (19) 213 (78)

16.2(2.0) 82.0 (17.1)

<0.6 (0.04) 1.06 (0.3)

8.5 (1.2) 24.9 (3.7)

191(87) 33 (7)

21.6 (5.1) 7.7 (0.7)

0.86 (0.1) <1.0 (0.3)

15.3 (0.3)

96 (10)

68.2 (1.9)

1.6 (0.1)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 5.4 (1.6) 7.8 (1.2) 7.1 (0.2)

Stem 16/05/2007

Loveday 1.9 (0.1)

2.8 (1.5)

26 (11)

1.3 (90.1)

<0.6 (na)

20/08/2008 22/04/2009

1.6 (0.1) 4.1 (1.2)

3.3 (0.2) 12.1 (4.2)

10 (1) 109 (38)

1.9 (0.1) 25.6 (12.7)

< 0.6 (0) < 0.6 (0)

16/05/2007

Henley Beach 2.66 (1.2)

2.3 (0.8)

28 (10)

1.72 (0.2)

<0.6 (na)

20/08/2008

1.67 (0.25)

2.1 (0.4)

6 (1)

2.4 (0.3)

< 0.6 (0)

22/04/2009

2.39 (0.66)

6.7 (2.4)

23 (6)

2.6 (0.5)

< 0.6 (0)

Rhizome Loveday 3.00(0.02)

3.4(0.8)

13.66(1.9)

2.5(0.1)

22/04/2009

2.78(0.44) 9.28(3.89)

4.36(1.11) 17.41(6.49)

6.53(0.82) 32.73 11.69)

2.8(0.4) 11.2(3.4)

16/05/2007 20/08/2008

Henley Beach 3.14(0.2) 3.98(1.12)

5.13(1.2) 4.62(1.01)

11.77(2.6) 4.54(0.85)

3.46(0.2) 3.90(0.46)

22/04/2009

5.91(2.51)

16.99(3.58)

15.40(1.99)

4.74(2.82)

16/05/2007 20/08/2008

114

<0.6(na) < 0.6(0) < 0.6(0)

<0.6(na) < 0.6(0) < 0.6(0)

Table 2.A.9: Average micro-nutrient removals concentrations for 3 annual clearfell harvests at Barmera. Standard error of the mean is shown in parentheses.

Treatment

Cu (g/ha)

Zn (g/ha)

Mn (g/ha)

B (g/ha)

Mo (g/ha)

Leaf Loveday 16/05/2007 44.8 (11.5) 20/08/2008 2.5 (1.1) 34.9 (1.8) 22/04/2009

91 (32) 11 (4) 100 (14)

2.4 (0.9) 77 (31) 1186 (320)

212 (68) 14 (7) 487 (116)

8 0.5 (0.2) 6.3 (1.8)

92 (45) 4 (3) 50 (6)

2.0 (1.3) 8.0 (6.4) 309 (27)

217 (95) 2. (2) 225 (30)

9.6 (4.2) 0.2 (0.1) 5.1 (0.5)

92 (38) 106 (34) 254 (58)

0.9 (0.2) 346 (111) 2147 (479)

45 (5) 66 (26) 4762 (195)

2 20.6 (7.8) 13.7 (2.8)

28 (10) 31 (6) 19 (3)

11 7.5 (1.1) 4.5 (0.4)

16/05/2007 20/08/2008 22/04/2009

Henley Beach 60.4 (29.4) 1.3 (0.8) 23.7 (4.2)

Stem Loveday 16/05/2007 67.1 (4.2) 20/08/2008 56.3 (23.8) 22/04/2009 87.9 (16.7) Henley Beach 58.8 (42.1) 20.3 (2.6) 17.2 (3.5) Tops Loveday 16/05/2007 111.9 (7.4) 20/08/2008 58.8 (24.8) 22/04/2009 122.8 (15.5)

31 (6) 24 (3) 49 (15)

0.5 (0.3) 69.8 (14.7) 184 (61)

182 (22) 118 (38) 353 (64)

3.3 (0.5) 422 (142) 3334 (744)

Henley Beach 16/05/2007 119.4 (23.0) 20/08/2008 20.4 (2.7) 22/04/2009 33.7 (3.7)

123 (25) 25 (3) 81 (12)

Rhizome Loveday 16/05/2007 79.7 (16.1) 20/08/2008 116.1 (28.8)

16/05/2007 20/08/2008 22/04/2009

22/04/2009

360.5 (86.1) Henley Beach 16/05/2007 53.0 (27.9) 20/08/2008 38.0 (10.2) 22/04/2009 51.9 (22.6)

257 (48) 80 (33) 964 (219)

30 21.0 (7.9) 20.0 (2.6)

2.5 (0.7) 70 (14) 506 (83)

246 (60) 31 (6) 214 (17)

20 7.6 (1.1) 9.4 (0.3)

98 (43) 174 (50)

0.4 (0.1) 275.1 (74.8)

67 (15) 117 (28)

16 24.5 (4.1)

689 (141)

134.7 (19.1)

27 (6)

27.0 (6.0)

68 (23) 0.21 (0.1) 46 (11) 44.0 (7.1) 149 (33) 1321.7 (292.8)

53 (23) 38 (5) 5 (1)

10 6.0 (0.6) 5.2 (0.1)

115

Table 2.A.10: Average meso-nutrient concentrations at Roseworthy for final harvest 2009. Standard errors of means are shown in parentheses.

Treatment

25/06/2009 25/06/2009

25/06/2009 25/06/2009

25/06/2009 25/06/2009

S

Ca

Mg

Fe

(%) Leaf Irrigated 0.56 (0.04) Dryland 0.32 (0.01) Stem Irrigated 0.13 (0.01) Dryland 0.12 (0.02) Rhizome Irrigated 0.40 (0.02) Dryland 0.50 (0.08)

(%)

(%)

(%)

0.71 (0.09)

0.29 (0.04)

0.01 (0.0004)

0.56 (0.04)

0.19 (0.01)

0.01 (0.004)

0.06 (0.003)

0.08 (0.01)

0.003 (0.001)

0.14 (0.03)

0.09 (0.02)

0.01 (0.004)

0.08 (0.01)

0.11 (0.005)

0.01 (0.001)

0.12 (0.01)

0.15 (0.03)

0.01 (0.001)

Table 2.A.11: Average meso-nutrient removals at Roseworthy for final harvest 2009. Standard errors of means are shown in parentheses.

Treatment

S kg/ha)

Ca (kg/ha)

Mg (kg/ha)

Fe (kg/ha)

31 (6)

12 (2)

0.54 (0.14)

15 (3)

5 (1)

0.24 (0.03)

39 (9)

53 (15)

2.04 (0.71)

5 (1)

3 (1)

0.39 (0.17)

66 (16)

2.66 (0.83)

Leaf 25/06/2009 25/06/2009

Irrigated 24 (6) Dryland 9 (2)

Stem 25/06/2009 25/06/2009

Irrigated 81 (15) Dryland 5 (1)

Tops 25/06/2009 25/06/2009

25/06/2009 25/06/2009

Irrigated 108 (22) Dryland 13 (2) Irrigated 210 (34) Dryland 135 (57)

72 (15)

21 (3) 8 (1) Rhizome

0.62 (0.14)

41 (6)

57 (9)

3.47 (0.66)

32 (10)

42 (18)

1.68 (0.71)

116

Table 2.A.12: Average micro-nutrient concentrations at final Roseworthy harvest 2009. Standard errors of means are shown in parentheses.

Treatment

Cu

Zn

Mn

B

Mo

(mg/kg)

(mg/kg)

(mg/kg)

(mg/kg)

(mg/kg)

90.0 (20.3)

27.8 (7.5)

< 0.6

31.2 (2.8) Stem

8.8 (0.4)

< 0.6

10.4 (1.3)

1.7 (0.2)

< 0.6

1.5 (0.1)

< 0.6

Leaf 25/06/2009 25/06/2009

25/06/2009 25/06/2009

25/06/2009 25/06/2009

Irrigated 3.5 (0.2) Dryland 4.1 (0.3) Irrigated 1.7 (0.2) Dryland 2.3 (0.1) Irrigated 2.8 (0.1) Dryland 2.0 (0.1)

19.7 (2.5) 15.7 (0.3)

5.8 (0.8) 5.8 (0.6)

6.4 (0.3) Rhizome

13.9 (0.5)

5.9 (0.9)

2.4 (0.4)

< 0.6

7.8 (0.1)

4.1 (0.4)

1.6 (0.2)

< 0.6

Table 2.A.13: Average micro-nutrient removals at Roseworthy for final harvest 2009 (25/06/2009). Standard errors of means are shown in parentheses.

Treatment /dates Irrigated 25/06/2009 Dryland 25/06/2009 Irrigated 25/06/2009 Dryland 25/06/2009

Cu (g/ha)

17 (6) 11 (1)

112 (35) 9 (2)

Irrigated 25/06/2009

131 (43)

Dryland 25/06/2009

20 (1)

Irrigated 25/06/2009 Dryland 25/06/2009

Zn (g/ha) Leaf

Mn (g/ha)

B (g/ha)

Mo (g/ha)

359 (56)

105 (17)

2.7 (0.8)

84(17)

23 (4)

1.6 (0.3)

612 (25)

103 (6)

39.6 (10.2)

26 (5)

6 (1)

2.4 (0.4)

1018 (42)

218(16)

42.7 (11.1)

66 (7) 110 (13) Rhizome

29 (3)

4.0 (0.3)

98 (41) 42 (6) Stem 405 (182) 24 (6) Tops 519 (236)

145 (20)

722 (91)

309 (72)

129 (33)

31.5 (4.7)

51 (14)

197 (50)

107 (36)

41 (13)

15.1 (3.9)

117

Appendix 4.A: Kraft pulp results for A. donax Pulping and ECF Bleaching of A. donax Work Carried out at Physical Chemistry, Pulping and Bleaching Division Central Pulp and Paper Research Institute, Saharanpur, India

Introduction A project entitled “Pulping and ECF Bleaching Of A. donax (Giant reed)” had the objective, using a sample provided by SARDI, from the Roseworthy, SA, field trial site, of producing unbleached pulp of A. donax by the kraft process maintaining a kappa number around 20, followed by Elemental chlorine free (ECF) bleaching of unbleached pulp by the DEpD sequence. Work plan Raw Material preparation Pulping of Reed to around 20 kappa number Unbleached pulp characterization for yield, rejects, kappa number, brightness and viscosity. DEpD bleaching of unbleached pulp Bleached pulp analysis for brightness and viscosity. Physical strength properties evaluation of bleached and unbleached pulp without beating.

Experimental Raw material Preparation: Raw material received from the sponsor was in stick form of around 25-30 inch length. The sample was manually chopped to length of 1-2 inch size and kept in polythene bags in order to retain uniform moisture content. Moisture content was determined by the standard TAPPI Method.

Pulping: Pulping experiments were carried out using different cooking chemical doses following the kraft process. Experiments were performed in a series digester consisting of six bombs of 2.5-liter capacity, rotating in an electrically heated polyethylene glycol bath. At the end of the cooking, the bombs were removed and quenched in the water tank to depressurize .The cooked mass from each bomb was taken for washing. Washing was carried out with hot water till the cooked mass was free from spent liquor. After thorough washing, the unscreened pulp yield was determined and the pulp was screened in a laboratory using a ‘Serla’ screen with a 0.25 mm. slot width mesh. The Kappa number of the screened pulp was determined as per the Tappi standard procedure T-236-OS-76. Bleaching: Unbleached pulp was bleached by the ECF( DEpD) bleaching sequence. The following bleaching conditions were maintained.

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Bleaching Conditions: Parameters

D Stage

Ep Stage

D1/D2 Stage

Consistency ,%

4

8

8

Reaction Time (Min.)

45

60

180

Reaction Temp. (0C)

50

70

80

pH

2-2.5

10.5-11.0

3-4

Viscosity and Brightness: Intrinsic viscosity of the pulp was measured by Scan procedure C-15:65. The brightness of the unbleached and bleached pulps was measured as per ISO method.

Physical Strength Properties Evaluation: Physical strength properties were evaluated as per the standard procedure. Strength properties were evaluated without beating the pulp, as per the sponsor’s requirements evaluated.

Results and Discussion: Pulping of A. donax: Pulping experiments were carried out using various dosages of cooking chemicals. The results of the pulping experiments are depicted in table 4.1. Table 4.A.1 - Pulping of A. donax

Parameters Raw material taken (g) Bath ratio Cooking Chemical applied as Na2O (%) Time to temp. 172 oC (min) Time At temp 172oC (min) Cooking Chemical applied as Na2O (%) Unscreened yield (%) Reject (%) Kappa number Brightness (% ISO) Viscosity (cc/g) Black liquor Analysis pH RAA (g/l as NaOH)

1

2

3

14 120 90 14 42.6 3.2 51

16 120 90 16 40.1 0.60 30.6

18 120 90 18 37.12 0.42 22.0 23.30 929.8

10.0 1.5

10.5 1.76

11 2.00

The reed has high chemical demand as given in the table above. With 14% chemical as Na2O the kappa number obtained was 51 while yield was 42.6%. A Kappa number of 22 was obtained by using 18% of chemical as Na2O, with an unscreened pulp yield 37.12%. The viscosity of this pulp is 929.8 cc/g.

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ECF Bleaching of unbleached pulp: ECF bleaching of unbleached pulp was carried out by DEpD sequence. Since the kappa number is high, kappa factor 0.3 is applied in first stage dioxide treatment. Table 4.A.2: DEpD bleaching of unbleached pulp

Parameters

Results

Kappa number

22.0

Brightness (%iso)

23.30

Viscosity (cc/g)

929.8

DEpD Stage D1 Stage Dioxide added as avl Chlorine (%)

6.6

pH

2.5

Consistency (%)

5

Temp. (oC)

50

Time (min)

60

Ep Stage Alkali added (% NaOH)

3.0

Peroxide added (%H2O2)

1

Consistency (%)

10

Time (min)

60

Temp. (o C)

50

DEp pulp brightness (%iso)

74.81

DEp pulp viscosity (cc/g)

802.9

D2 Stage Dioxide added as D (%)

1

pH

3.5

Consistency (%)

10

o

Temp. ) C)

80

Time, min

180

Brightness (%ISO)

86.5

Viscosity (cc/g)

791.4

Shrinkage/ yield (%)

4.5/95.5

The brightness obtained in tree stage bleaching was 86.5 maintaining viscosity 791.4. Bleaching response of reed pulp is good with substantial intrinsic fibre strength.

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Physical Strength Properties of Unbleached and bleached pulp Results of physical strength properties of A. donax bleached and unbleached pulp are depicted in table 4.A.3. Table 4.A.3 - Physical Strength Properties

Parameters

Freeness, (csf) ml

Burst index

Tear index

Tensile (N.m/g)

(Kpa.m2/g)

(mN.m2/g)

Unbleached Pulp

635

1.80

8.90

31.0

Bleached Pulp

520

1.60

8.0

25.0

Physical strength properties indicate that A. donax (reed) has substantial strength without refining, which can be further enhanced after refining pulp to standard freeness.

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Appendix 4.B: Bisulphite pulping of A. donax Peter de Morton, Nafty Vanderhoek and Michael Wedding, (CSIRO Material Science and Engineering, Monash Campus, Clayton, Victoria, Australia) Important Disclaimer CSIRO advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.

Executive Summary Exploratory laboratory tests have been undertaken to determine the feasibility of replacing part of the fibre furnish at Tantanoola/Millicent with A. donax in tissue and other sanitary products1. It has been found that P. radiata could be pulped to 30 kappa number using magnesium bisulphite pulping (also known as the Magnifite process). Replacement of the fibre furnish with 20% Adx whilst maintaining processing conditions constant, resulted in a pulp of lower yield (51.3% compared with 54.0%) and kappa number (27.5 compared with 31.2), poorer in strengths (5-15%), duller in appearance (54.4 compared with 62.2 ISO brightness) and higher in “dirt” content. Based on this assessment, the use of Adx in tissue and sanitary products may have to be restricted to levels well below 20%.

Conclusions and Recommendations A summary of the main points are: It is possible to produce magnesium bisulphite pulp at 30 ± 3 kappa number with a fibre furnish containing up to 20% Adx For a fixed set of cooking conditions, the presence of Adx in the pulping mix as 1-2 cm “sticks” results in faster cooking and a lower yield at a kappa number. The P. radiata/Adx pulp is lower in quality by 5-15% while visual appearance is also inferior with handsheets made from this pulp being both duller and higher in “dirt” content. Based on the limited work carried out, the use of Adx in tissue and sanitary products may have to be restricted to levels lower than assessed here (5-10%). It is recommended that no further work be done on this aspect of the study as the main objective of the work has been fully met. Any additional pulping work should be directed to areas where visual appearance and pulp strength are less of any issue, such as for packaging grades.

Background SARDI and FibreCell have embarked on a project to assess Adx as a potential source of fibres for pulp and paper manufacture. In August 2008, Mr David Paul, FibreCell approached CSIRO Material Science and Engineering (CMSE) to assist them in evaluating Adx available from a low salt site at Roseworthy, SA. Subsequently, agreement was reached1 for CMSE to undertake laboratory pulping studies with the major objective to determine the suitability of Adx as a part fibre replacement in

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magnesium bisulphite pulping2. The work is being undertaken as part of a RIRDC funded project titled “Commercial potential of giant reed for pulp/paper and biofuel production”. Over the past decade, there has been renewed interest in Adx as a potential fibre source, and its response to different pulping processes is well documented (see references in this chapter). The reasons for this are several-fold and varied; its high biomass yield, early maturity and annual harvest. The work reported in this study is very much preliminary in nature. A number of process steps, of which pulping is but one, must be successfully encountered before any new fibre source can be considered for pulp and paper manufacture. Failure to pass any of these hurdles would seriously limit Adx as a potential fibre source.

Objectives The objectives of the study were: •

To establish the impact of replacing part of the fibre input at Millicent/Tantanoola with Adx in magnesium bisulphite pulping.

•

To evaluate the potential of using P.radiata/Adx pulp in tissue and sanitary products

•

To provide appropriate technical advice to the SARDI/FibreCell on the value of Adx as a potential fibre source to the Kimberley Clark pulp mill at Millicent, SA.

Outputs/Deliverables The work undertaken has provided an initial analysis of the impact of replacing part of the fibre furnish at KCC with Adx. There would appear to be some difficulties in using up to 20% Adx in the fibre furnish with the pulp being of lower yield and quality, both in strength and visual appearance.

Results and Discussion Before discussing the results from this study and its major implications, it is informative to explain in some detail, to those less skilled in the art, the major steps involved in the manufacture of pulp and paper, and their broad importance.

1

Project proposal 2008093093 entitled “Pulping of A. donax”, dated 29 September 2008 2

This option was chosen after consideration of the site of the Adx and location of the nearest commercial pulping facility

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Preamble There are two basic operations which need to be considered in assessing the value of any fibre source such as Adx. The first is pulping which involves the separation of fibres present in wood (or nonwoods) into a form suitable for papermaking and the second encompasses the various steps of forming the fibres into a sheet of paper or paperboard. In addition to the above, knowledge of the most likely end-product application is desirable as it allows a decision to be made on the properties which should be measured from the wide range of tests that are available. Conventional pulping may be classified into three main types. In mechanical pulping, separation of the fibres is achieved largely through mechanical attrition. Thermomechanical pulping (TMP), refined mechanical pulping (RMP) and pressurised ground wood refining (PGR) are examples of mechanical pulping. Pulps produced in this manner are high in yield (usually above 90% weight percent) but low in strengths. Such pulps are commonly used in newsprint manufacture. At the other extreme is chemical pulping where dissolution of the fibres is achieved by chemical means. Kraft pulping, where the active chemical reagents are sodium hydroxide and sodium sulphide, soda pulping in which caustic soda alone is used as the cooking agent, and sulfite or bisulphite pulping where solubilisation of the lignin is attained by sulfonation are examples of chemical pulping. Chemical pulps exhibit high strengths but yield is normally below 50 percent. Pulps formed in this manner find widespread application in packaging grades, printing and writing papers, and tissue and sanitary products. Sulfite pulps contain a higher proportion of cellulose and are used for viscose and tissue manufacture. Semi-chemical pulps are prepared by subjecting the fibrous material to milder chemical treatment which is insufficient to liberate the fibres. Mechanical action on the softened material is then used to free the fibres. Neutral sulfite semi-chemical (NSSC) pulping, which involves the use of sodium sulfite in combination with sodium carbonate, is the best known of the semi-chemical processes, the pulps from which are primarily used in corrugating mediums and flutings. Not surprisingly, semichemical pulps are intermediate in yield (ca. 70 percent) and strengths are between chemical and mechanical pulps. The pulps described above are all commodity trade items which may be sold on the market either unbleached or bleached. In bleaching, the pulp is “whitened” by treatment with reagents that specifically attack lignin such as dithionite, oxygen, hydrogen peroxide and chlorine containing chemicals. Bleached pulps are more expensive to produce and usually command a higher price. They are used in a wide range of products where optical properties such as brightness, light scattering coefficient and dirt count are important. Papermaking machines effectively comprise three sections; a wet end where the sheet is formed, a press section where excess water is pressed from the sheet, and a drier section where residual water is removed by passing the sheet over heated cylinders. The machine may operate at speeds of up to 2000 m/min (equivalent to 120 km/hr), so drainage is an important criterion. All paper and board machines require the fibre furnish to drain rapidly to maximise production speed. A slow draining pulp is less attractive economically than a faster draining pulp of equivalent strength. In practice, the classification of pulps produced by different treatment methods into product classes can be less clear-cut than indicated above. Thus for example, some chemical pulp may be used in newsprint manufacture to aid runnability on the paper machine. Likewise, linerboards and cartonboards are composed normally of a number of pulp layers where the outside layer is virgin chemical pulp and the inner plies are composed of semi-chemical pulp or recovered fibre. It is also common to blend long fibre softwood with short fibre hardwood in many applications in order to conserve resources, optimise key mechanical properties and increase economic returns.

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As mentioned above, chemical pulps are used commonly in a variety of applications eg. packaging grades, tissue and sanitary products, and printing and writing grades, each of which require performance criteria which differ from one application to another. A summary of the different papers, the major grades within, their functional requirements and annual production is given in Table 4.B.1. Properties of importance for tissue and sanitary papers are softness, absorbency, cleanliness and wet tensile strength. The standard strength properties (dry tensile, burst and tear) are not as important because adequate levels are usually achieved with the type of pulps used in tissue and sanitary product papers. Table 4.B.1: Summary of types of paper

Paper category

Major grades (not comprehensive)

Functional requirements

Tissue and Towelling Facial tissues, toilet tissue, kitchen towel, paper napkins Packaging and Industrial Papers

Newsprint

Printing and Writing Papers

Water absorbency, softness, wet strength, cleanliness, optical Boxboard (linerboard Compressional and corrugating strength, tearing medium), strength, abrasion cartonboard, bag and resistance, printing sack papers performance Newsprint, directory Moderate printing papers performance, moderate whiteness, short lifespan Copy paper, High quality printing uncoated woodfree performance, high printing paper, whiteness or colour coated woodfree uniformity and printing paper, stability, surface lightweight coated smoothness, paper dimensional stability TOTALS

Annual Australian production and [Imports] – tonnes 2007 (Appita4) 214,000 [56,000]

1,839,000 [256,000]

410,000 [328,000]

591,000 [949,000]

3,054,000 [1,589,000]

In a study as broad and limited as the present investigation it is simply not possible to carry out handsheet testing for all properties of possible interest and yet complete the work within a reasonable time frame and cost. In such cases, it is common practice to split the study into smaller investigations, corresponding to important go/no-go decision points. Such an approach has been chosen in this investigation with an initial emphasis on pulping, the first key step in the assessment of any new fibre resource. To achieve the objective, two sets of handsheets have been prepared from bisulphite pulping of P. radiata in the absence and presence of Adx, and some selected properties compared. 4 Source: Appita’s Guide to the Australian and New Zealand pulp and paper industry, pg 5 (2007).

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Bisulphite Pulping The results of the magnesium bisulphite pulping experiments of P. radiata chips in the presence and absence Adx are given in Table 4.B.2, while relevant comments on the properties of interest follow in the subsequent sections. Table 4.B.2: Summary of magnesium bisulphate pulping results.

Pulping Cook Cooking details Pine Arundo donax Liquor to wood ratio Magnesium bisulphite Final temperature Time to temperature Total cooking time Residual bisulphite Final pH Pulp yield Screen rejects Total yield Pulp yield plus 2/3 screenings Kappa number Strength properties Freeness Grammage (conditioned) Density Tear Index Tensile Index Stretch Work Index Ext. Stiffness Index Burst Index Air Resistance Optical Properties Opacity (ISO) ISO brightness Colour L* Colour a* Colour b*

g OD g OD % oC

min min g/l % % % %

csf g/m2 kg/m3 mNm2/g Nm/g % mJ/g kNm/g kPam2/g s/100ml

1

2

3

4

5

600 0 4:1 17.1 165 180 249 6.6 3.5 51.0 10.5 61.5 58.0 63.1

600 0 5.5:1 21.0 165 180 280 7.3 nd 51.9 5.6 57.5 55.6 48.0

600 0 5.5:1 25.0 165 180 286 12.2 nd 53.7 3.7 57.4 56.1 43.5

600 0 5.5:1 27.0 165 180 295 8.1 3.4 52.3 2.5 54.8 54.0 31.2

480 120 5.5:1 27.0 165 180 298 8.9 3.4 49.3 3.1 52.4 51.3 27.5

-

-

-

650 67.9 732 8.3 72.8 2.1 992 8.3 4.3 8.3

650 68.1 723 8.6 63.4 2.0 848 7.9 3.5 9.0

60.9 88.6 - 0.9 11.3

76.5 62.2 89.0 -0.8 11.1

83.7 54.4 85.5 -0.2 11.9

% 56.8 86.9 -0.3 12.5

5

60.6 88.4 - 0.8 11.3

L*, a* and b*are colour coordinates that discriminate samples on a white (100L*)/black (0L*), red (+a*)/green (-a*) and yellow (+b*)/blue(-b*) scale respectively 6 The difference is difficult to capture via digital photographs.

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It was possible to achieve the aimed kappa number (30±5 units) but this required chemical loading (27% on OD fibre) considerably higher than anticipated, based on information available to the authors. The reason for this is unclear, but may be related to the use of tap water for dilution rather than deoxygenated water. However in the context of the present study, this is not regarded as critical. All the other key parameters such as total cooking time, final pH and residual bisulphite were within the expected range. It is normal practice in bisulphite pulping to aim for a residual chemical of between 5-10g/l. Extending the cook beyond this level can result in “burning” of the pulp. There was no evidence of this having occurred in the pulping work reported here. Cooks 1 to 3 were sighter tests in that pulps with kappa number higher than desired were obtained. Pulp close to the aimed kappa number was achieved with cooks 4 and 5. Thus in the laboratory, it is possible to obtain a pulp from 100% P. radiata chips at 54.8% total yield and 31.2 kappa number using 27% magnesium bisulphite on OD wood. Replacing 20% of the fibre source with Adx resulted in a reduction in yield of 2.4 units to 52.4% and a lowering in kappa number by 3.7 units to 27.5.

20

25

30

35

40

45

50

55

60

65

70

Kappa number Yield Expon. (Yield) Figure 4.B.1: Relationship between total pulp yield and kappa number (100% P. radiata)

The relationship between total pulp yield and kappa number for 100% P. radiata is shown in Figure 1 for the data presented in Table 4.B.2. Based on this narrow yield range and a limited number of cooks, it would appear that a 1 percent reduction in pulp yield corresponds to a lowering in kappa number of 5 units. Thus for the mixed furnish (cook 5) and the total yield obtained (52.4%), a pulp at 20 ± 2 kappa number might have been expected which is considerably lower than that determined. There are several possible reasons for this: • Adx contains more water or acid soluble materials than P. radiata • The lignin in the Adx is more highly polymerised to that in P. radiata • The delignification process slows down as pulp yield decreases • Adding the Adx as short “sticks” inhibits liquor penetration when compared with P. radiata chips None of the above factors are regarded as potential “show-stoppers”; however any further work of this nature should investigate the impact of Adx size distribution on pulping behaviour.

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Strength Properties Figure 4.B.2 displays graphically the pulp strength data listed in Table 4.B.2. Due care needs to be taken when interpreting this data as it represents results from single cooks only. Nevertheless, it would appear that the replacement of 20% of the fibre furnish with Adx reduces pulp strengths by 5 to 15%. Equally worrisome is the higher value obtained for air resistance with P. radiata/Adx sheets as this could reflect the presence of non-fibrous elements that are known to inhibit pulp drainage on paper machines. The measurement of pulp drainage time should be carried out as part of any future study. Whether a lowering in pulp quality at the level indicated above is a major concern is an issue that would need to be discussed with KCC technical staff. In some respects, the reduction in pulp properties obtained in this study is not surprising as biometric characteristics (1) of Adx implies it has a fibre length closer to typical eucalypts but is considerably coarser. Such fibres would be expected to pack less tightly in a paper sheet, lowering both bonding strength and density i.e. the results summarised in Table 4.B.2 are consistent with this theory.

Optical Properties

Property Figure 4.B.2: Comparison of pulp strength properties (100% P. radiata used as control).

The visual and measured appearance of handsheets made from 100% P. radiata or 80:20 P. radiata/Adx mix are different as reflected in the inspection handsheets shown in Appendix 4.B.iii. The presence of Adx fibres gives rise to a sheet that is duller (lower brightness and lightness [L*]5), more opaque (higher opacity) and contains more debris6. The variation in colour coordinates for the two different set of pulps is due, at least in part, to differences in the chemical composition of the raw materials as shown in Figure 4.B.3 which displays P. radiata and Adx as “flour”. The P. radiata wood meal is creamy in colour compared with the Adx which has a “greenish – yellow “tinge. It is apparent that not all the coloured materials present in the Adx are removed during the magnesium bisulphite pulping process.

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Figure 4.B.3: Samples of subdivided P. radiata (right) and Adx (left)

Elemental Analysis Table 4.B.3 summarises the results from the elemental analysis of P. radiata and Adx. In addition to the measurement of sodium and chloride content, data on hot water extractives, ash content and dichloromethane (DCM) solubles are also given as these tests are simple to do and highly informative. With the exception of DCM solubles, all tests are done on woodmeal, the form needed to do the elemental analysis. The Adx is characterised by having similar ash content and DCM solubles, but a level of hot water extractives four times higher than found in P. radiata. This would explain the lower yield obtained when co-pulping Adx and P. radiata. The ash content of Adx is characterised by a low calcium level, but high silicon and chloride content when compared with P. radiata. The higher chloride content in Adx was confirmed by two methods; Mohrs titration (quantitative) and EDS (qualitative) and could have implications on tendency for plant equipment to corrode.

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Table 4.B.3: Summary of the woodmeal and pulp analysis

Unit

P. radiata

Adx

Method

Hot water extractives

%

2.8

11.4

TAPPI T207 cm-99

Ash content

%

3.1

3.4

TAPPI T211 om-93

Dichloromethane solubles

%

1.1

1.2

TAPPI T280 pm-99

Parameter

Ash composition

By EDS7 (quantitative)

• Sodium

%

3.5

2.9

• Magnesium

%

24.2

16.0

• Silicon

%

2.9

19.1

• Phosphorus

%

5.1

4.5

• Sulphur

%

4.3

7.1

• Chloride

%

<0.1

12.5

• Potassium

%

32.4

32.5

• Calcium

%

28.1

4.5

• Sodium

ppm

0.4

0.5

By AA8

• Chloride

ppm

4.5

17.5

Mohrs titration

Elemental

7

Energy Dispersive Spectroscopy

8

Atomic Absorption Spectroscopy

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References Abrantes, S, Amaral, ME, Costa, AP, Shatalov, A and Duarte, AP 2007, - Evaluation of giant reed as a raw-material for paper production. Appita Journal, vol.60, no.5 pp.410-415. Byrd, MV 2000, ‘The pulping, bleaching and papermaking characteristics of reed (A. donax) compared with mixed southern hardwoods’, Proceedings, 2000 Fourth International Nonwood Fibre Pulping and Papermaking Conference, Jinan, vol.1, pp.122 – 129. Caparros, S et al 2006, ‘A. donax L. Valorisation under hydrothermal and pulp processing’, Industrial Engineering Chemical Research, vol.45, p.2940. Coelho, D et al 2007, ‘Chemical characterization of the lipophilic fraction of giant reed (A. donax) fibres used for pulp and paper manufacturing’, Industrial Crops and Products vol.26, p.229. Shatalov, A 2002, ‘Ethanol-enhanced alkaline pulping of A. donax L. reed: Influence of solvent on pulp yield and quality’, Holzforschung vol.56, no.5, p.507. Shatalov, A, and Pereira, H 2004, ‘A. donax L. reed: New perspectives for pulping and bleaching – 3, Ethanol-reinforced alkaline pulping.’ Tappi Journal, vol.3, no.2, p.27. Shatalov, A, and Pereira, H 2005, ‘Kinetics of organosolv delignification of the fibre crop A. donax L.’, Industrial Crops and Products vol.21, p.203. Shatalov, A, Quilho, T, and Pereira, H 2001, ‘A. donax L. reed: New perspectives for pulping and bleaching – 2, Organosolv delignification.’ Tappi Journal, vol.84, no.11, p.1.

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Acknowledgements The authors wish to thank Dr Chris Williams, SARDI, Mr David Paul, FibreCell and Mr Stephen Say, (Kimberley Clark Company, KCC) for their contribution to the project in supplying information and samples on request.

Materials and Methods Fibre materials Adx (CW – ADX1; 10 kg fresh) from a low salt site at Roseworthy was supplied by Dr Chris Williams, SARDI as bare stems, 20-30 cm in length and on receipt stems cut into smaller fragments (25 ± 2 mm) by means of a band saw (refer Figure 4.B.4).

Figure 4.B.4: Sample of Adx as received (left) and after cutting with a band saw (right)

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Sawmill chips were a sample arranged by KCC and was received in wet form. The wood/nonwood characteristics are given in Table 4. Table 4.B.4: Summary of the wood/non-wood properties

Basic Density (kg/m3) 499 390 Unit

P. radiata

Adx

Method

%

2.8

11.4

TAPPI T207 cm-99

%

3.1

3.4

TAPPI T211 om-93

%

1.1

1.2

TAPPI T280 pm-99 By EDS7 (quantitative)

9

%

3.5

2.9

%

24.2

16.0

Information provided by Dr Alan Farrington

Preparation of bisulphite pulping liquor Magnesium bisulphite liquor was prepared by passing sulphur dioxide gas, ex cylinder through a slurry of magnesium oxide powder in chilled deionised (DI) water (refer Figure 5). After the addition of the calculated quantity of sulphur dioxide to convert the available magnesium oxide to the bisulphite, the solution was allowed to stand overnight in a cold room. The bisulphite liquor was adjusted to pH 4.5 by the addition of magnesium oxide. To make an approximately 8% solution containing 250g Mg(HSO3)2 requires 54g MgO, 172g SO2 and 3.1L of chilled water9. The liquor was analysed for magnesium bisulphite content by taking an aliquot (10mL) of the liquor and diluting to 100mL with DI water. An aliquot (5mL) of the diluted liquor was placed in a flask to which was added DI water (100mL), potassium iodide (1M; 5mL) and sulphuric acid (4N; 5mL), and the total mixture titrated with potassium iodate (0.0132M) until the solution turned blue. The residual magnesium (g/L) equals the titre multiplied by 7.3925

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Figure 4.B.5: Preparation of bisulphite pulping liquor (left) and analysis of the prepared liquor (right)

Pulping Pulping was carried out in a 7.5 litre stationary digester (refer Figure 6). All cooks were carried out with the same rise to temperature, but the time at temperature varied. Typical cooking conditions were as follows: Charge: 600 g OD chips; liquor to wood ratio 5.5:1; 3 h to temperature plus 1.5-2.0 h at temperature10; Cooking chemical as shown in Table 4.B.2.

Figure 4.B.6: Picture of digester (left) and liquor extraction point (right) 10

When the residual bisulphite in the spent liquor dropped below 10 g/litre

The cooked chips were washed twice with tap water (approximately 4-5 litres) in the digester for 3-5 minutes each. The pulps were disintegrated with a propeller agitator (10 min, 2% consistency, 1425 rpm) and passed through a Packer screen with 0.25 mm slots. During screening, the filtrate was recycled until all fines were retained. The pulp was thickened in a centrifuge with fines retention and the yield (screened and total) and kappa number determined. Residual bisulphite and pH were measured on the spent liquor.

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Residual bisulphite To an aliquot of spent liquor (5mL) was added DI water (100mL), iodine (1M; 5mL), sulphuric acid (4N; 5mL). The total mixture was titrated with a potassium iodate solution (0.0132M) to a blue end point. The residual bisulphite (g/L) was determined as the titre (mL) multiplied by 0.73925.

Testing All handsheet testing was performed according to the Australian (Appita) standard method AS/NZS 1301.208s:1997 – Physical testing of pulp handsheet and individual test standards referenced therein.

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Appendix 4.B.i: Pulp and Papermaking Terms This section provides a listing of pulp and papermaking terms used in the body of this report using definitions found in J.R. Lavigne – Pulp & Paper Dictionary, MF publications, USA, Abrasion Resistance: The ability of a paper product to withstand abrasion. It is measured by determining the degree and rate that a sample loses weight under the specific rubbing action of an abrading substance such as an eraser or various abrasive papers. Air Dry (AD): Refers to weight of moisture-free pulp or paper plus 10% moisture based on the traditional assumption that this amount of moisture exits. Air-dried weight is determined by dividing the oven-dried (OD) weight by a factor of 0.9. Bag Paper: Any paper made to be used in the manufacture of bags. Beating: The process of mixing pulps together with various materials, such as dyes and additives, in a mechanical device called a beater. By means of the mechanical actions of crushing, cutting and brushing the fibres, beating will impart properties that determine the characteristic of the ultimate paper or board product. Beating is the oldest of the stock preparation processes. Bisulphite Pulping: The process of making pulp from wood chips using bisulphite cooking liquor containing the bisulphite ion (HSO3-) in the 2 to 6 pH range with little or no free SO2. Bleaching: The process of purifying and whitening pulp by chemical treatment to remove or change existing colouring material so that the pulp takes on a higher brightness characteristic. It is carried out in single or a sequence of several stages. Brightness: A measure of the degree of reflectivity of a sheet of pulp or paper for blue light measured under specified standard conditions. Same as whiteness. Bursting Strength: The resistance of paper to rupture when pressure is applied to a side by an instrument. It is usually determined on a Mullen tester and expressed in kilopascals per square metre (pounds per square inch). Sometimes referred to as burst, mullen or pop strength. Cellulose: The chief substance in the cell wall of plants used in pulp manufacturing. It is the fibrous substance that remains after the non-fibrous portions, such as lignin and some carbohydrates, are removed during the cooking and bleaching operation of a pulp mill. Consistency: A measure of the fibrous material in pulp solutions, e.g. pulp and water or stock (pulps and additives) and water. It is expressed as a percentage of bone dry (BD), oven dry (OD) or air dry (AD) weight. Corrugating Medium: Paperboard that is made from chemical and semi-chemical pulps, sometimes mixed with straw or recycled fibre paper stock, that is to be converted to a corrugated board by passing it through a corrugating machine. Defibration: To mechanically reduce fibrous materials such as chips, pulp sheets, paper sheets etc., into their fibre components. Density: With reference to paper and paperboard sheets, it is the ratio of the weight to the volume, with high-density paper and paperboard having a high weight to volume ratio. It is the inverse of bulk.

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Digester: A pressure vessel used to chemically treat chips and other cellulosic material such as straw, bagasse, rags etc., under elevated temperature and pressure in order to separate the fibres from each other. Dimensional Stability: A sheet characteristic indicative of its ability to maintain original machine and cross-machine dimension with time, and under variable moisture and relative humidity conditions. Drainage time: The amount of time it takes for water to drain away from a stock slurry and form a mat on a standard size screen under specified conditions in a laboratory test procedure. Drier Section: Used interchangeably in paper mills with dryer, referring to paper machine equipment used to dry paper by evaporation of moisture by the use of steam. Edgewise Compression Strength: The ability of corrugated paperboard to withstand crushing pressure in the direction of the fluting. End Product: Finished and converted paperboard made into items ready to be utilised by the user. Extractives: Woody plant components which are not part of the cell wall structural elements and can be removed with neutral solvents such as ether, alcohol and water. Fibre: An elongated, tapering, thick-walled cellular unit which is the structural component of woody plants. They are separated from each other during the pulping operation in a pulp mill and reassembled into the form of a sheet during the papermaking process in the paper mill. Flute: One of the triangular shaped configurations formed by an undulation of the inner corrugated liner in corrugated-type paperboard similar to and sometimes known as corrugation. Freeness: The ability of a pulp and water mixture to release or retain water on drainage. The ease or lack of ease with which the mixture or slurry will drain is sometimes referred to as slowness or wetness. Furnish: The materials in a pulp stock mixture such as the various pulps, dyes, additives and other chemicals blended together in the stock preparation area of the paper mill and fed to the wet end of the paper machine to make the paper or paperboard. Commonly called stock. Handsheet: A single sheet of paper, made in the laboratory, used in testing and examining the properties of pulp and paper. Sometimes referred to as test sheet. Hardwood: Pulpwood from broad-leaved dicotyledonous deciduous trees. Kappa Number: A value obtained by a laboratory test procedure for indirectly indicating the lignin content, relative hardness or bleachability of higher lignin content pulps. Kraft Process: Means “strength” in German and is the common name for the sulphate chemical pulping process. Lignin: A brown-coloured organic substance which acts as an interfibre bond in woody tissues. It is chemically separated during the cooking process and is removed along with other organic material during subsequent washing and bleaching stages.

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Linerboard: A type of kraft paperboard, generally unbleached, used to line or face corrugated core board (on both sides) to form shipping boxes and various types of containers. Some linerboard may contain recycled fibre from small amounts to 100 percent. Liquor-to-Wood Ratio: The relationship between the total liquid added to a pulp digester, plus the moisture in the wood, and the bone-dry wood fed or loaded to the digester. Mechanical Pulp: Pulp produced by reducing pulpwood logs and chips into their fibre components by the use of mechanical energy via grinding stones, refiners etc. Newsprint: A grade of paper containing a high percentage of groundwood pulp made especially for the use of printing of newspapers. Nonwood Pulp: Papermaking pulps such as bagasse, bamboo, esparto, straws, cotton etc., not made from pulpwood trees but from other fibrous plants. Optical Properties: Those properties of pulp, paper and paperboard that are associated with light absorption and light-scattering. Oven Dry (OD): Moisture-free conditions of pulp and paper and other materials used in the pulp and paper industry. Packaging Paper: All grades of paper made especially for use in wrapping and making up packages for bundling and shipping purposes. Paperboard: A thick, heavy weight, rigid, single or multi-ply type of paper. Thickness and material vary depending on end use. It is used for wrappings, packaging, boxes, cartons, containers, advertising, merchandising displays, building construction etc. Also known simply as board. Press Section: That part of the paper machine located between the wet end section where water is removed by passing the wet web between rolls and felts while applying a combination of pressure and vacuum. Pulping Processes: Processes for converting fibrous raw material into pulp. They are usually classified by either the nature or degree of the chemical and/or mechanical treatments used in the pulping action. Quality: A reference to the “goodness” of paper and paperboard which is the sum of those properties and physical characteristics of importance to the user. Runnability: An indication of how well pulp stock furnish to the paper machine forms a sheet on the wire and passes through drying and finishing operations. Screenings: Rejected materials such as knots, shives and large particles from the screening operations of pulp suspensions in a pulp mill. Semichemical Pulp: A two-step pulping process which uses a mild liquor for partial softening of the chips followed by final separation of fibres by mechanical means. Softwood: Wood obtained from evergreen, cone-bearing species of trees such as pines, spruces, hemlocks etc., which are characterised by having needles.

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Smoothness: The surface property of a paper sheet related to its degree of uniform evenness or flatness. It is sometimes measured by the rate of air between two or more sheets or between one sheet and a smooth standard surface. Spent Liquor: Used cooking liquor in a chemical pulp mill which is separated from the pulp after the cooking process. Sulphite Process: An acid manufacturing process in which chips are reduced to their component parts by cooking in a pressurised vessel using a liquor composed of calcium, sodium, magnesium or ammonia salts of sulphurous acid. Tear Strength: The resistance of a paper sheet to tearing. It is usually measured by the force required to tear a strip under standardised conditions. Tensile Strength: The resistant property of a sheet to pull or stress produced by tension. It is expressed as force per unit width of a sample tested to the point of rupture. Thermomechanical Pulp (TMP): A wood-pulping process in which chips are pre-steamed before an initial refining treatment under elevated temperature and pressure, with subsequent refining treatment at atmospheric pressure. Tissue Paper: Thin, low weight, gauze-like types of paper made from virgin and/or reclaimed pulp used to manufacture such items as sanitary products, wrapping material, protective packing paper etc. Unbeaten Pulp: Pulp fibre that has not undergone any type of mechanical treatment with particular reference to beaters. Unbleached Pulp: Pulp that has not been treated in a bleaching process and can be used as in inferior grades of paper or paperboard. Wet End: The section of the head end of a paper machine which includes the headbox, wire and wet press section where the sheet is formed from the stock furnish and most of the water is removed before entering the press section. Yield: The ratio of the total amount of raw material entering a pulp and papermaking operation to the equivalent product output usually expressed as a percentage.

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Appendix 4.B.ii: Photographs of Equipment Used This section gives a collection of digital photographs of equipment used in this study and not covered elsewhere

pH meter/autotitrator Chips immediately after pulping

Pulp disintegrator Pulp plus screenings

Packer screen Hobart mixer Tear tester Tensile tester

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Burst tester Air permeance Figure 4.B.7: Collection of photographs from process steps and testing equipment

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Appendix 4.B.iii: Inspection Handsheets

P. radiata / Adx mix (80:20) showing more shives/dirt Figure 4.B.8: Digital photos of selected handsheets

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Wijte, AHBM, Mizutani, T, Motamed, ER, Merryfield, ML, Miller, DE and Alexander, DE. 2005, ‘Temperature and endogenous factors cause seasonal patterns in rooting by stem fragments of the invasive giant reed, Arundo donax (Poaceae)’, International Journal of Plant Science, vol.166, no.3,pp.507-517. Williams CMJ, Biswas TK, Harris P, Heading S 2008, Use of giant reed (Arundo donax) to treat wastewaters for resource recycling in South Australia, in Proceedings of the 5th International Symposium for Irrigation of Horticulture Crops, Mildura, Australia, Convenor: I. Gordon. Acta Horticulturae vol.792, pp.701-707. Williams CMJ, Biswas TK, Harris P, Heading S, Marton L, Czako M, Pollock R and Virtue J (2009) Use of poor quality water to produce high biomass yields of giant reed (Arundo donax L.) on marginal lands for biofuel or pulp/paper. Procs. of the Int. Symposium on Underutilized Plants for Food Security, Nutrition, Income and Sustainable Development. Convenor: H. Jaenicke. Acta Horticulturae vol.806, pp.595-602. Williams CMJ, Harris P, Biswas TK, Heading S 2006, ‘Use of giant reed (Arundo donax) to treat wastewaters for resource recycling in South Australia’. Poster presented at the 5th International Symposium for Irrigation of Horticulture Crops, Mildura, Australia, September, 2006. Williams CMJ, Maier NA 1990, ‘Determination of the nitrogen status of irrigated potato crops. 1. Critical nutrient ranges for nitrate - nitrogen in petioles’. Journal of Plant Nutrition vol.13, pp.971-984. Williams CMJ, Maier NA, Bartlett L 2004, Effect of molybdenum foliar sprays on yield, berry size, seed formation, and petiolar nutrient composition of "Merlot" grapevines. Journal of Plant Nutrition vol.27, pp.1891-1916. Williams CMJ, Maier, NA, Chvyl, L Porter, K and Leo, N 2007, ‘Molybdenum foliar sprays and other nutrient strategies to improve fruit set and reduce berry asynchrony (‘hen and chickens’)’, Final report project no. SAR 02/09b to the Grape and Wine Research and Development Corporation, May, 2007, by SARDI, pp. 212. Williams CMJ, Vitosh ML, Maier NA, MacKerron DKL 1999, ‘Nutrient management for sustainable potato (Solanum tuberosum) production systems in the southern and northern hemispheres’. In 'Solanaceae IV'. (Eds M Nee, DE Symon, RN Lester, JP Jessop) pp. 443-458. (Royal Botanic Gardens: Kew). Williams, C and Biswas, T 2009, Salinity tolerance, nutrient needs, weed risk management and carbon sequestration of Arundo donax for remediation of highly saline wastewaters for biofuel or pulp/paper feedstock production. Final report project No. 56/208, SA MurrayDarling Basin Natural Resources Management Board. September 2009, Publ. SARDI. Williams, C, Porter, K and Biswas, T 2008c,. ‘Improved nutrient and irrigation management strategies for Australian horticulture’, Proceedings of the national and Trans-Tasman Horticultural Science Conference, Surfers Paradise, Australia. 21-23 July, pp. 33 (abstract). Williams, C, Biswas, T, Black, I, and Heading, S 2008, Pathways to Prosperity: Second generation biomass crops for biofuels using saline lands and wasterwater. Agricultural Science vol. 21, no.1: pp.28-31. Williams, CMJ and Allden, WG 1976, ‘Economic returns from annual pastures sown at different seeding rates’. Proceedings of the Australian Society of Animal Production, vol 11, pp. 321-324.

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Commercial Potential of Giant Reed for Pulp, Paper and Biofuel Production by Dr Chris Williams and Dr Tapas Biswas Publication No. 10/215

This report presents research on the perennial, rhizomatous grass, giant reed (Arundo donax) to assess its use on marginal lands and wastewaters or saline ground waters, to produce lignocellulosic feedstocks (together with other biomass crops) and as new second generation biofuels and/or pulp/paper industries for Australia. A. donax produced more cellulosic biomass and sequestered more carbon per annum, using less land and pesticides than any other alternative crop reported in the literature, for warm temperate to sub tropical environments and for marginal lands under similar water input regimes. This report is targeted at all sectors of the Australian and overseas biomass, second generation biofuels and the pulp/ paper industries. The report is also intended to inform landcare

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