The Chicago Council is pleased to launch a new blog series, “Breaking Ground,” to explore how food systems innovation and agricultural research and development can empower farmers and feed the world.A special subsection of our series, “Field Notes,” features voices from Feed the Future Innovation Labs and CGIAR centers.
A woman holds a maize seedling. Photo: Dakshinamurthy Vedachalam/CIMMYT
International agricultural research has come a long way since the Green Revolution of the 1970s – from a tight focus on crop improvement to a wider quest for sustainable food systems. Our original objective, as the founders of International Maize and Wheat Improvement Center (CIMMYT) and other CGIAR Research Centers were fond of saying, was to increase the pile of grain. Now, we strive to achieve food and nutritional security in ways that also enhance rural livelihoods, reduce environmental degradation, and boost agriculture´s resilience.
How did this marked shift in our aims and way of working come about?
From the start, our scientists understood the need for better crop management to realize the benefits of new high-yielding cereals. They also soon grasped the importance of social and environmental impacts stemming from massive adoption of new crop technology. As the sustainable development paradigm gained wide acceptance from the early 1990s on, we embraced a new approach aimed at sustaining productivity growth through better management of soil and water as well as crop improvement, while also fostering equity through farmer participatory agronomy and economics research. In recent years, increasing clarity about the threat that climate change poses for agriculture has reinforced our commitment to what we refer to now as “sustainable intensification.”
But can this more demanding approach deliver major impacts comparable to the enormous benefits that have resulted from the spread of improved cereal varieties over the last half century? South Asia´s vast Indo-Gangetic Plain offers an especially appropriate setting in which to seek answers. It is a major regional food basket, whose predominant rice-wheat rotation, covering about 12 million hectares, provides food for hundreds of millions of consumers.
The Green Revolution took hold across this region during the 1970s. Within two decades, however, extensive surveys of the rice-wheat system had detected a steady decline in the productivity of both crops, mainly as a result of soil degradation. Meanwhile, widespread pumping of water from aquifers to irrigate cereals led to severe groundwater depletion in certain areas. The increased pressure on soil and water was driven to a large degree by government policies that gave first priority to national food security, depending heavily on rice and wheat. Gains in the productivity of these crops came at the expense of food system diversity and efficient resource use. In response, researchers refined and intensively promoted zero tillage and other resource-conserving practices.
The Indo-Gangetic Plain thus became a major proving ground for efforts to put the concept of sustainable intensification into practice, which offer important lessons for other regions as well. Recent research has brought the challenge into sharp focus, underlining the need for solutions that combine sound policies with robust technologies and institutional support to address thorny trade-offs between increased crop productivity and environmental protection.
Getting the right mix in place is not easy, however. In 2009, state governments in Northwest India implemented a policy designed to reduce groundwater extraction by prohibiting the usual practice of planting rice in May and moving it instead to June, nearer the start of monsoon rains. Although the policy did succeed in alleviating pressure on groundwater, it also had the unexpected effect of worsening already severe air pollution. The reason, according to a recent study published in Nature Sustainability, is that the delay in rice planting narrowed the window between rice harvest and sowing of the subsequent crop, mainly wheat, leaving farmers little time to remove rice straw from the field and compelling them to burn it instead. Delayed wheat planting would have resulted in significant yield losses. Even though burning crop residues is prohibited in India, uncertainty about the implementation of government policy and a perceived lack of alternatives have perpetuated the practice in Haryana and Punjab states, near the nation´s capital, New Delhi, where air pollution poses a major health threat.
Decades of research for development have fortunately enabled CIMMYT together with the Indian Council of Agricultural Research (ICAR) and many other partners to identify pathways out of this conundrum. One especially potent solution centers on the practice of zero tillage, in which wheat seed is sown immediately after rice harvest through the rice straw directly into untilled soil with a single tractor pass.
Extensive research has shown that zero tillage lowers farmers´ production costs, preserves soil and water, and reduces greenhouse gas emissions by eliminating the need to burn rice straw, while also cutting the fuel consumption of farm machinery. In addition, it increases wheat yield by eliminating the need to prepare a seedbed between rice and wheat sowing and thus enabling farmers to plant wheat at the optimum time, i.e., around 3 weeks earlier than with traditional tillage.
Farmer using a tractor fitted with a Happy Seeder. Zero tillage reverses the loss of soil organic matter that happens in conventional tillage. Photo: Dakshinamurthy Vedachalam/CIMMYT
Zero tillage requires the use of a special, tractor-mounted implement, called the Happy Seeder, which makes it possible to sow wheat through a thick cover of rice straw. Zero tillage using the Happy Seeder emerged as the clear winner in a recent evaluation of 10 alternatives for handling rice straw, with and without burning. Reported in a Science Magazine paper, the results show that using the Happy Seeder not only reduces greenhouse gas emissions by 78 percent, compared to burning, but also raises farmers´ profits by 10-20 percent.
Making zero tillage work also depends on a combination of agronomic and breeding solutions. With traditional wheat varieties, early sowing of wheat was difficult, because high temperatures caused the plants to grow too quickly, lowering yields. New wheat varieties slow down this early development, giving 1 ton more grain per hectare than with the traditional practice.
In Northwest India, farmers are rapidly taking up the combination of new wheat varieties and zero tillage with the Happy Seeder; estimated adoption currently stands at about 0.8 million hectares. Beyond the immediate benefits, this represents an important step toward adapting the region´s agriculture to climate change impacts, which include higher temperatures and more variable rainfall.
A new government subsidy has lowered the cost barrier to further spread of this technology, but much more remains to be done. Research organizations, universities, NGOs, and the private sector all have important roles to play in fostering increased manufacture and rental of the machine through private service provision and in conducting demonstrations and training.
No single alternative, however effective, will be sufficient to resolve the trade-offs around rice-wheat production in Northwest India. For that reason, researchers have identified other options as well, such as earlier maturing rice varieties and laser land levelling. Using a guided laser beam to achieve uniform slope throughout a field with a specialized tractor-drawn implement, this practice has already been adopted on millions of hectares in Haryana and Punjab, leading to more efficient irrigation as well as higher yields.
Researchers also propose a more fundamental shift away from current incentives to maximize the region´s cereal production. This would entail increased support for cereal production in the eastern Gangetic Plain, where water is more abundant and integrated crop-livestock production offers alternative uses for rice straw.
Coming back to the question of impact raised earlier, the answer from our collaborative experience in South Asia is a qualified “yes.” While the adoption figures for zero tillage are modest compared to those for adoption of new cereal varieties, they are still significant, representing multiple benefits for millions of adopting farmers and for society as a whole. Research in India on zero tillage and other alternatives demonstrates clearly that balancing food security, rural livelihoods, water for agriculture and air quality need not be a zero-sum game. Part of the payoff from this work, intangible but valuable nonetheless, is well-founded hope for a sustainable future.