Paul Truong, Dnr, Brisbane, Australia

VETIVER VETIVER GRASS GRASS TECHNOLOGY TECHNOLOGY FOR FOR ENVIRONMENTAL ENVIRONMENTAL PROTECTION PROTECTION Paul Truong, DNR, Brisbane, Australia Vetiver VetiverGrass GrassTechnology Technology(VGT) (VGT)was wasfirst firstdeveloped developedby bythe theWorld WorldBank Bankfor forsoil soiland andwater waterconservation conservationininagricultural agricultural lands in the 1980’s. The Vetiver Network (TVN) with the support of the World Bank, has since encouraged, lands in the 1980’s. The Vetiver Network (TVN) with the support of the World Bank, has since encouraged,supported supported the theR&D R&Dand andpromoted promotedthe theapplication applicationofofVGT VGTworld worldwide widethrough throughits itsglobal globalnetwork. network. One Oneofofthe theoutstanding outstanding successes of its R&D is the applications of VGT in the area of environmental protection. successes of its R&D is the applications of VGT in the area of environmental protection. Tolerance Range of Vetiver Grass

Several attempts in the past to rehabilitate this old quarry have failed. Vetiver was planted in this highly hostile environment to control soil erosion

Deep and extensive root system binds the soil and enhances drought tolerance

Nine months after effluent was released upslope from the vetiver stand. Note the excellent growth of vetiver on the RHS and poor growth on the LHS, indicating most if not all the discharged effluent was soaked up by the first few rows of vetiver.

pH 3.3 Between 80% - 87% > 578 mgkg -1 pH 11.5 17.5 mScm -1 47.5 mScm -1 33% (exchange Na) 2 400 mgkg -1 (Mg)

Heavy Metals Arsenic Cadmium Copper Chromium Nickel Mercury Lead Selenium Zinc.

100 - 250 mgkg -1 20 mgkg -1 35 - 50 mgkg -1 200 - 600 mgkg -1 50 - 100 mgkg -1 > 6 mgkg -1 > 1 500 mgkg -1 > 74 mgkg -1 >750 mgkg -1

Location

Equator to 41 0N

Climate Annual Rainfall (mm) Frost (ground temp.) Heat wave Drought (without effective rain)

250 - 5 000 -14 0C 55 0C 15 months

Fertiliser Vetiver can be established on very infertile soil due to its strong association with mycorrhiza

Sixteen months after planting, this old quarry was successfully revegetated and the inter row space was all covered with volunteer species.

Vetiver was planted to soak up effluent from septic tanks on a holiday camp. General view of the camp with vetiver well established 7 months after planting.

Adverse Soil Conditions Acidity Aluminium level (Al Sat. %) Manganese level Alkalinity (highly sodic) Salinity (50% yield reduction) Salinity (survived) Sodicity Magnesicity

Vetiver grass planted across this waterway on a sugarcane farm in Australia to control erosion and to trap sediment runoff from the sugarcane fields. Note the large quantity of sediment trapped after one big storm.

In Guangzhou, China, leachate and odour from this newly disposed city garbage will pollute the environment if not properly rehabilitated.

This 40 year old coal mine overburden stock pile remains bare of vegetation. Several rehabilitation attempts have failed

Dense growth retards water flow and traps sediments

N and P (300 kg/ ha DAP)

Pesticide concentrations in sediment trapped up and downstream of 2 vetiver filter strips. The green bars indicate the position of the 2 vetiver rows in the waterway. This shows that up to 88% of the pesticides in the runoff water was trapped by the hedges.

Following capping with a thin layer of topsoil Vetiver was planted on top of this landfill.

Vetiver established successfully in the gully to stop further erosion and across the toe slope to trap eroded material

Herbicieds concentrations in sediment trapped up aand downstream of the two vetiver hdges. At the second hedge, most of the herbicide was also trapped.

One year after planting the landfill was successfully rehabilitaed.

Dust pollution is a major environmental hazard in semi arid regions and mining operations. This photo shows the dust problem on the tailings dam of a gold mine.

When planting at a certain interval, vetiver hedgerows will reduce wind velocity at ground leveland promote the establishment of the ground cover crop. This combination