Mar 21, 2011
Planting without Ploughing: zero-till wheat takes root explains how innovative partnerships among researchers and farmers have enabled the adoption of zero-tillage cultivation on nearly two million hectares in the Indo-Gangetic Plains. The practice is increasing farmers' incomes, fostering sustainable use of soil and water, and providing a platform for other resource-conserving practices.
The Indo-Gangetic Plains (IGP), which spread from Pakistan across northern India, southern Nepal, and into Bangladesh, are the breadbasket of the Indian sub-continent and home to more than 300 million people. Farmers in the region typically grow two crops per year: monsoon-season flooded rice and winter season wheat. However, since the 1990s, productivity increases in the rice-wheat rotation have stagnated, owing to land degradation and late planting of wheat, in particular.
Typical farming practices involve up to eight tractor passes to restructure rice paddy soils before planting wheat. Not only is this costly in diesel and associated CO2 emissions, but the later the wheat is planted, the more likely the crop will suffer from pre-monsoon heat during grain filling, significantly reducing yields. To keep pace with the region’s exploding food demands and to adapt to water shortages and climate change, farmers need technologies that can help them improve yields while saving resources, cutting production costs and sustaining environmental quality.
Zero-tillage - the direct seeding of wheat into unploughed paddies following rice harvest - offers a more sustainable alternative: it involves a single tractor pass, thereby saving fuel, cutting greenhouse gas emissions, and allowing the earlier planting of wheat. The International Maize and Wheat Improvement Centre (CIMMYT) began to introduce this practice throughout the IGP in the 1980s, with efforts increasing with the involvement after 1994 of the Rice-Wheat Consortium (RWC). DFID has supported the work of RWC both directly, and through on-going core assistance to CIMMYT.
Rapid adoption of zero-tillage in the region, especially in India, began in the late-1990s. During 1997-2004, around 620,000 farmers adopted the system and zero-tillage wheat cultivation now covers an estimated 1.76 million of the 14 million hectares of rice-wheat cultivation. This uptake has led to important direct outcomes for farmers and the environment.
Many factors contributed to the successful spread of zero-tillage in the IGP. A key one was the collaborative development and local manufacture of affordable zero-tillage seed drills - which in one pass place wheat seed and fertiliser directly into unploughed land. The process of testing prototype seed drills on farmers’ land with farmer participation, developing drills suited to local conditions, and making them available to farmers at an affordable cost, were all vital steps. Seed drills were attractive both for farmers keen to reduce their own cultivation costs and hire themselves out for direct-seeding of neighbours' fields, as well as for profit-minded local manufacturers. Crucial as well were the use of farmer participatory approaches and the involvement of farm implement manufacturers and input suppliers to promote and support zero-tillage against the opposition of tradition-minded farmers, researchers, and policymakers. Finally, the development and spread of this innovation owes much to the conviction and hard work of national research programme champions and extension agents, as well as the continuing high-quality training and support they received through the RWC and CIMMYT.
Apart from reducing cultivation costs, the zero-tillage method increases wheat harvests by 5-7 per cent, largely thanks to timely planting. As a result, in India, it is estimated that zero-tillage has increased incomes by US$97 per hectare, with households typically increasing their annual earnings by US$180-$340. The bulk of this is from reduced costs. Zero-tillage also has environmental benefits: reducing fossil fuel use and greenhouse gas emissions, improving both fertility and water-holding capacity of the soils, reducing rates of soil erosion, and encouraging rice-wheat farmers to leave crop residues on the soil surface rather than burning them.
Furthermore, reduced tillage has provided a "platform" for introducing other resource-conserving practices such as: sowing on raised beds; surface seeding in riverain areas; smallholders in the eastern IGP using laser levelling to improve irrigation efficiency; cropping diversification (introducing, for example, pulses and vegetable crops); and supporting conversion to full conservation agriculture by replacing puddled rice cropping with aerobic rice cultivation. Such practices will be crucial for the region, given that by 2050 climate-change induced heat and water stress in irrigated areas may reduce wheat yields by 12 per cent and rice by 10 per cent, while the unsustainable extraction of water for agriculture continues to drain aquifers.