Brochure Pg Socieconom Icarda

The profitability and constraints of phosphogypsum application on sodic soils: The case of Arys Turkestan in Southern Kazakhstan Authors: V. Muhamedjanov, N. Gritsenko, V. Vishpolskiy, S.Ibatullin, A. Mirzabaev, A. Aw-Hassan, R. Paroda, M.Qadir, A. Noble, A.Karimov

Problem definition Soils with high levels of magnesium have low infiltration rates and hydraulic conductivities, these soils form big clods when dry at post-irrigation phase, which negatively impacts on the water infiltration. Such sodic soils are predominant in Ukraine, Russia, Kazakhstan, Eastern Europe, China, Canada, USA, South Africa and Australia in the area of about 135 million hectares. The consequence is a gradual decline in crop yields. This study evaluates the potential impacts and identifies the constraints of using phosphogypsum as a remedy in such soils. More than

30% of the irrigated area in Southern Kazakhstan has soils with high levels of magnesium, which results in a decline in cotton yields, thus, affecting the livelihoods of many poor rural households who heavily rely on this crop. Leaching of soils with excess water application at the rates 2500-3500 m3/ha have been a common practice for decades, resulting in the removal of excess soluble salts as well as essential nutrients. The present insufficient use of mineral fertilizers in the area further exacerbates the problem.

The research site ICARDA initiated the on-farm researches on PG application in Arys Turkistan area, which represents the irrigated systems of Central Asia. The research was funded by the ADB project on Soil and Water Management, which was conducted in six countries in Central Asia and the Caucasus. During 1999 to 2005 the Kazakh National Water Management Institute implemented the PG trials in the study area. Since 2005, these trials have continued in partnership with the same Institute under under a joint IWMI-ICARDA-ICBA project on Saline Soils Management also funded by the ADB. Southern Kazakhstan, where the research site is located, is one of the most important agricultural areas in Kazakhstan, where the majority of the country's irrigated agricultural land is situated, and has both the highest population density and the highest poverty incidence.

Is phosphogypsum a feasible option? This study examines whether Phosphogypsum (PG) can be a viable solution for remediation of high magnesium contaminated soils in Southern Kazakhstan. PG efficiently improves the soil fertility by impacting positively on the soil structure through recovering its water permeability. The gypsum it contains also serves as a valuable source for phosphate, calcium and other elements needed by the plants. PG application in Southern Kazakhstan was first initiated in early 1980s; however,

Figure 1. During a farmers’ field day on phosphogypsum application (Arys Turkestan, Kazakhstan)

with the changes in the agriculture after the collapse of the Soviet Union, PG application has completely disappeared. Phosphogypsum can be applied in winter before snowfall or after plowing the field for seed-bed preparation. In low rainfall years, incorporation of the applied phosphogypsum by harrowing the field is recommended in order to reduce the risk of the material being blown away due to strong winds that are common in the region. The positive effect of phosphogypsum on crop yields last for a minimum 4 years after application, though starting from the third year it gradually begins to decline.

PG supply and costs There appears to be abundant supply of PG in two fertilizer factories in Taraz and Chimkent both located in South Kazakhstan, as these factories have accumulated several million tons of PG as an industrial by-product during their operation for the last 50 years. Currently, PG is dumped in openair near the production sites of these factories that are a potential environmental hazard. The cost of procurement either in Taraz or Chimkent plus transportation and application are estimated at 31 USD/t. However, there are PG supply shortages due to other uses such as in construction, etc in Chimkent as well as concerns of quality. Such concerns are not reported in Taraz. Figure 1 shows that transportation accounts for the largest share (85%) of the total cost of PG use, where as only 15% is the actual procurement and loading cost. This makes transportation cost as the single most important factor affecting the large scale adoption of PG application.

Total cost: 31.5 USD for t/ha Procurement of PG , 4.72

Trans portation, 26.78

Figure 1. Cost structure of PG application

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BOX: The positive affects of PG application in agriculture and the constraints to a large scale application.

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T he positive affects Improves the soil quality b y increasing water perm eability, thus increasing a nd stabilizing crop yields a nd increasing farm incom e. C ontains m ineral fertilizers, which enrich the soil w hen dissolved, thus contributing vitally im p ortant nutrient elem ents to th e soil. H elps to alleviate the environm ental hazards caused b y its op en-a ir du mp ing near chem ical factories.

T he co nstraints F arm ers’ awareness of the technology is still low. F arm ers, in their majority, currently don’t have sufficient financia l resources for phosphogypsu m application, w hich necessitates active public financial support in dissem ination of this technology.

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Economic evaluation of PG application

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The profitability of PG application was evaluated using on-farm trial data from farmers' fields in Arys Turkestan. The project conducted on-farm trials on the application of phosphogypsum (PG) on soils with high magnesium levels at Arys Turkestan site in Kazakhstan where 5 different treatments were applied. These treatments include control (or no PG application) and application in autumn before snowfall at the rates of either 3.3 t ha-1 or 8.0 t ha-1 -1 and application in spring at the rates of either 3.3 or 8.0 t ha . The valuation is based on cost benefit analyses of on-farm enterprise budgets of each of the treatments. The cost benefit analysis is a technique for evaluating the total costs of one or more technologies with their total benefits. Technology is considered as profitable when the cost benefit ratio is higher than 1. Rate of return (ROR) is used to evaluate the return from investing in PG application. ROR is the ratio of profits gained or lost on an investment relative to the amount of money invested. We collected the production costs data including variable (inputs) and fixed costs (taxes and depreciation) through interviews with farmers participating in the trials. Results Figure 2 presents the net benefits per hectare during the fist year of PG application on cotton under the five treatments. The analysis shows that the application of PG in autumn before snowfall is better than its application in spring, the average Benefit Cost Ratio (BCR) for the first option is 1.2, and 1.05 for the second option. The results revealed that, at least during the fist year, the application of PG in spring did not generate any additional revenues when compared to the no- PG control treatment. In addition, under the treatments where 3.3 t/ha of PG was applied more net benefits were generated than under those where 8.0 t/ha of PG applied.

150 100 50 0 NO PG

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3.3 t/ha PG 8.0 t/ha PG before snowfall before snowfall

3.3 t/ha PGin spring

8.0 t/ha PGin spring

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Figure 2. Net Accumulated benefits per hectare (USD/ha)

This is due to the fact that additional yield increases associated with higher PG rates did not generate enough net benefits to cover the increased PG application costs. Though, it

should be noted that as the PG's impact lasts about 4 years, even spring application of PG and its application at the rate of 8.0 t/ha could eventually become more profitable than no-PG treatment. During the first year, the 3.3 t/ha of PG application was found to be more beneficial than 8.0 t/ha of application, the average BCR for 3.3 t/ha of PG application was 1.2, for the 8.0 t/ha of application it was 1.0. The internal rate of return from applying 3.3 t/ha of PG in autumn before snowfall against the no-PG treatment was 55%. The average ROR was 120% for 3.3 t/ha of application, whereas for 8.0 t/ha of application it was negative (2%). The average ROR for PG application in autumn was 90%, and for spring application it was 28%.

Constraints Currently, PG is not marketed by fertilizer traders in Kazakhstan for agricultural users because there is no wide scale application of PG in agriculture for remediation of soils in Southern Kazakhstan, thus economies of scale and stable demand for PG by farmers is currently not present. Once, the application of PG becomes widespread, and the demand for PG increases, fertilizer traders may respond by supplying PG as any other fertilizer. At the same time, PG is not listed as a fertilizer, thus farmers willing to apply PG are not able to benefit from Government subsidies for fertilizers.

Conclusions Phosphogypsum application has demonstrated a big potential for remediation of magnesium dominant soils in Southern Kazakhstan. Profitability analysis shows that high PG application that produce the highest crop yields did not generate the highest net incomes. Lower rate at 3.3 t/ha applied in autumn before snowfall was found to generate the highest economic benefit. Subsidies for PG application rates in the initial period to promote adoption and develop the market supply system can be

Contacts: International Center for Agricultural Research in the Dry Areas (ICARDA), Central Asia and Caucasus Regional Office, Murtazaeva 6, Tashkent, 700000, Uzbekistan. Tel: (998) 71 137 21 30/137 21 60 E-mail: [email protected]

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