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Focus
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| New
Technologies for Central Asia |
Mekhlis
Suleimenov, Mustafa Pala, Raj Paroda, Kanat Akshalov, Firuza Khasanova,
Luidmila Martynova, and Rakhim Medeubaev |
 No-tillage direct drill equipment plants legumes on wheat stubble, leaving most of the straw on the soil surface. |
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In 2004 ICARDA and its partners launched a research project to arrest land and soil degradation in Central Asia, with funding from the Asian Development Bank. The partners include CGIAR centers, governments, and national institutions. The project focuses on two areas – conservation tillage and crop diversification. Two years into the project, the impacts are already becoming evident.
To till or not to till?
Conventional tillage is the process of turning over the soil with a plow, to increase aeration and water infiltration, improve texture, and control weeds. In principle, that's good. But in practice, the disadvantages of heavy and/or frequent tillage often outweigh the benefits. A better option is conservation tillage – a more environment-friendly approach that can reduce costs and slow down land degradation, without sacrificing yield.
Plowing in Central Asia (and most parts of the world) is usually done with a moldboard plow, which overturns the soil, burying organic matter from the previous harvest and bringing fresh soil to the surface. It was originally designed for ‘sod busting’ when bringing new land under agriculture. But when used on previously tilled land, the benefits are limited; and regular heavy tillage can cause soil damage.
One alternative is zero tillage – crops can be successfully grown for several years with no tillage at all, but this requires large investments in equipment and herbicides. Instead, ICARDA promotes conservation tillage, which is more suitable for resource-poor small-scale farmers. The aim is to reduce the number of tillage operations to the minimum needed to maintain yield; and to leave organic matter (e.g. crop residue) on the soil surface instead of burying it. Conservation tillage saves time, effort and tractor diesel, reduces erosion (because the soil surface is not left bare), and also prevents long-term damage to soil structure.
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Locally
made no-tillage direct drill equipment in northern Kazakhstan.
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Different systems, different solutions
Central Asia consists of three climatic zones: the icy northern steppes of Kazakhstan, the somewhat warmer foothills (Kazakhstan and Kyrgyzstan), and the southern region comprising Uzbekistan, Tajikistan and Turkmenistan, with long hot summers. The farming systems are correspondingly different. Agriculture in the northern steppes is based on rainfed spring wheat. The middle region has a mixture of rainfed and irrigated agriculture and grows winter wheat. The south produces mainly cotton and wheat under irrigation.
The project aims to promote conservation agriculture in all three regions, by developing and testing solutions tailored to each zone.
In spring wheat systems, field experiments have shown that tillage can be greatly reduced without reducing grain yield; but continuous zero-tillage is bad for heavy textured soils. The key question is the soil's permeability to water during the planting season in early spring. Because the soil is generally frozen at this time, snowmelt water runs off the surface unless the soil is broken up by tillage, allowing water to penetrate. The project has introduced "zero-tillage planters", which are actually a form of minimum tillage, where the mechanized planter breaks up the surface sufficiently to allow water penetration. Last season, these planters were used for sowing spring wheat on about 100,000 hectares in northern Kazakhstan, and more farmers are keen to acquire the new equipment.
In rainfed winter wheat systems, the project has shown that conservation tillage produces similar yields to moldboard plowing, at the same depth. We tested a conservation tillage system in southern Kazakhstan for four years: zero tillage at planting and minimal tillage in the off-season, for mulching and leveling. The results showed how complex the problem can be. Yields actually fell in low-rainfall areas, because reduction in tillage led to more soil compaction, reduced availability of nitrates, and more weeds. However, the yield loss was partly compensated by savings in labor and fuel. In areas with higher rainfall, conservation tillage increased yields, and adoption is growing.
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Demonstration plot showing alternatives to monocropping: more diverse, productive, and sustainable. |
In irrigated cotton-wheat systems, experiments showed that replacement of moldboard plowing with minimum tillage reduced cotton yields, but not wheat yields. So we developed and tested a modified system – use the moldboard plow for cotton, as before; later, use minimum tillage for wheat, i.e. broadcast wheat seeds (without tillage) into standing cotton, and bury the seeds during the tillage operation normally done to control weeds in the cotton crop. Thus, the extent of tillage is reduced, but not eliminated. This practice has been adopted very widely. It is popular with farmers in 50-60% of wheat areas in Uzbekistan and Tajikistan, and 20% in Turkmenistan.
The project is also introducing another innovation into cotton-wheat systems, where plants are grown on raised beds. Because the beds do not cover the entire field, less seed is needed – but raised beds improve yield, so the harvest is the same as before. On-farm tests in southern Kazakhstan and Azerbaijan show that raised beds give a slight increase in output, while cutting seed requirements by half, and water consumption by 30%.
The problem is that these technologies require mechanized equipment, which is not locally available. The project is working with Indian manufacturers of raised-bed planters, to develop a modified version that will be manufactured in Kazakhstan. Similarly, no-till planters from India and Brazil were tested in Kazakhstan, Uzbekistan and Tajikistan, and can be used for planting winter wheat as well as cotton and double crops.
In Uzbekistan the project tested new conservation tillage equipment specially designed to plant wheat on cotton fields. The machinery can perform several tillage operations in one run: uprooting cotton plants after harvest, chopping them up and spreading the pieces on the soil surface, sowing wheat seeds, and cutting irrigation furrows. Initial results are highly promising.
In summary, conservation tillage is recommended for every region in Central Asia; but efficiency and cost-effectiveness will depend on soil conditions, rainfall, temperatures, and crops grown. By tailoring solutions to each farming system, the project is helping farmers maximize yield without destroying their soils.
Simultaneously, the project is also looking at ways to increase the efficiency of conservation tillage, for example by applying optimum fertilizer and plant protection chemicals in small quantities.
Crop diversification for sustainable farming
Traditional cropping systems have developed over many years to suit local conditions and minimize climate risk. However, new crops can offer substantially better returns without increasing risk. ICARDA and its partners are promoting new crop options in each of the three zones in Central Asia.
In the spring wheat systems of northern Kazakhstan, the project is testing new technologies that could double or triple farmers' incomes. Traditionally, wheat and/or barley is planted in spring (second half of May) and harvested in September. Every three to five years, the land is left fallow for almost 2 years; typically 21 months, September to May. The project is testing a more profitable alternative: Rotate wheat/ barley with other crops such as small grains (oats, millet, buckwheat), food legumes (dry pea, chickpea, lentil), and oilseeds (sunflower, rapeseed, mustard). Equally important, instead of leaving land fallow in summer, grow legumes – an extra crop that also increases soil fertility.
The project studied various options for summer cropping. Chickpea and dry pea gave particularly good results; both are adapted to local conditions, rich in protein, and could become valuable cash crops. A crop management package was developed and tested, and proved to be highly effective (Fig. 1). Chickpea is a new crop and adoption is still limited; with some government support to establish markets, it could take off.
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Oilseeds, also being promoted by the project, are taking hold. Sun-flower area is increasing, because an internal market is available and prices are good. The Kazakhstan government also plans to promote rapeseed production on a large scale (about 160,000 hectares in 2006) and provide subsidies to producers and processing industries for the next three years.
In the winter wheat zone, farmers are gradually shifting away from wheat to safflower in rainfed areas and soybean and common bean in irrigated areas. Safflower is an excellent cash crop. Adoption is growing not only in southern Kazakhstan and Kyrgyzstan but also in the drylands of Uzbekistan; the size and speed of this expansion generally depends on government policies. In Kazakhstan the government began aggressively promoting soybean cultivation in 2003; area has increased almost nine-fold in the past three years (currently 43,000 hectares). Soybean and common bean production is also increasing in Kyrgyzstan.
Another new crop is alfalfa. Long-term trials in southern Kazakhstan showed that alfalfa could be adopted on a large scale in semi-arid conditions to improve land productivity, economic efficiency, and sustainability; the main constraint is lack of seed and seed production equipment.
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Conservation tillage in northern Kazakhstan, leaving residues on the soil surface. |
Finally, the irrigated cotton-wheat system in the southern zone. Land availability is limited; so double cropping is probably the best option to introduce new crops. Several crops have done well in field trials in all three countries: food legumes, mung bean, soybean, common bean, maize, sesame, groundnut, and melons. However, governments in these countries do not promote widespread adoption of double cropping because of competition with cotton for water. Double cropping (sugar beet and rice) is being promoted only in Turkmenistan.
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Sunflower cultivation is growing rapidly, thanks to strong domestic markets and good prices. |
New systems
New crops and modified cropping systems offer a range of benefits – higher incomes, better nutrition, less degradation, and a healthier farming system. Low-cost technologies are available, and have been tested on a pilot scale. But to scale them out, specific constraints must first be resolved. In some cases the problem is lack of seed, equipment, or funds. But more often it is lack of policy support. Development agencies must work with government policy makers to ensure that systems diversification and conservation agriculture are given the emphasis they deserve.
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| Dr Raj Paroda (r.paroda@cgiar.org) and Dr Mekhlis Suleimenov (m.suleimenov@cgiar.org) are Coordinator and Deputy Coordinator, respectively, of ICARDA's CAC program, based in Tashkent, Uzbekistan. Dr Mustafa Pala (m.pala@cgiar.org) is Senior Agronomist at ICARDA, based in Aleppo. Kanat Akshalov (Kanat@kepter.kz) is head of the Crop Management Dept., Grain Farming Research Institute, Shortandy, Kazakhstan. Dr Firuza Khasanova and Dr Luidmila Martynova are heads of the Soil Tillage Laboratory at Cotton Research Institute, Tashkent, and the Research Institute of Soil and Crop Management, Kyrgyzstan, respectively. Dr Rakhim Medeubaev is Head of Agronomy Dept., Krasniy Vodopad Research Station, Kazakhstan. |
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