Researchers and policymakers are promoting zero tillage for wheat to stop rice residue burning in northern India and help prevent smog in New Delhi, as well as to cut farmers’ costs and conserve soil and water resources.
Farmers who deploy a sustainable agricultural technique known as “zero tillage” in the rice-wheat cropping rotations grown throughout northern India can significantly contribute to reduced air pollution in India’s capital, helping urban dwellers breathe more easily.
Traditional tillage to sow wheat in northern India involves removing or burning rice straw and driving tractor-drawn implements back and forth over fields to rebuild a soil bed from the rice paddy, a costly and protracted process.
Media reports in 2016 depicted the 19 million inhabitants of New Delhi under siege from a noxious haze generated by traffic, industries, cooking fires and the burning of over 30 million tons of rice straw on farms in the neighboring states of Haryana and Punjab.
Since the 1990s, scientists at the International Maize and Wheat Improvement Center (CIMMYT) have worked with national agricultural partners and advanced research institutes in India, Nepal, and Pakistan to test and promote the resource-conserving approach of sowing wheat seed directly into untilled soil and rice residues in a single tractor pass, a method known as zero tillage.
Originally deemed foolish by many farmers and researchers, the practice or its adaptations are being used on as much as 1.8 million hectares in India. It has gained popularity because it allows farmers to save money and fuel through less work and tractor use, to reduce weather risks as well as to sow their wheat up to two weeks earlier; this means the grain fills before the withering heat of pre-Monsoon season.
Environmental benefits of zero tillage include healthier soils, significant water savings and a 90 kilogram-per-hectare reduction in greenhouse gas emissions, according to M.L. Jat, senior agronomist at CIMMYT.
“This emission savings figure considers only soil respiration,” said Jat, “but if we talk about carbon sequestration based on life cycle analysis, the greenhouse gas savings range from 500 to 1,000 kilograms of carbon dioxide equivalent per hectare, each crop cycle.”
The seeder drives adoption
Zero tillage requires the use of a special, tractor-mounted implement, which, in a single pass, chops rice residues, opens a rut in the soil, and precisely deposits and covers the seed.
Development of this special seeder was first funded by the Australian Centre for International Agricultural Research (ACIAR) and led by Punjab Agricultural University, with contributions from CIMMYT and other organizations. The latest version, the Turbo Happy Seeder, costs $1,900 – an investment that many farmers still struggle to make.
“As an alternative, we’ve been saying that not all farmers need to own a seeder,” according to Jat. “Many farmers can simply hire local service providers who have purchased the seeder and will sow on contract.”
In Bihar and the neighboring state of Uttar Pradesh, the number of zero-tillage service providers rose from only 17 in 2012 to more than 1,900 in 2015, according to Jat, who leads CIMMYT’s contributions to “climate-smart” villages in South Asia, as part of the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).
Given New Delhi’s smog troubles, Haryana and Punjab policymakers are providing limited subsidies for purchases of the seeder and other policy support for burn-free, climate-smart agricultural practices.
Work on the Turbo Happy Seeder has been funded by the Australian Centre for International Agricultural Research and the CGIAR Consortium and Fund Council. Zero tillage for rice-wheat rotations is one of the technologies studied and promoted by the CIMMYT-led Cereal Systems Initiative for South Asia, a project implemented jointly with the International Food Policy Research Institute and the International Rice Research Institute and funded by the Bill & Melinda Gates Foundation and the United States Agency for International Development. The Borlaug Institute for South Asia (BISA) is funded by the Indian Council of Agricultural Research and, for the work described, by the government of Punjab state, India.
Text: G. Michael Listman
Contributors: M.L. Jat, H.S. Sidhu
Photos: S. Mojumder Drik, Neil Palmer/CIAT, Mandeep Singh/CIMMYT
Graphics: Gerardo Mejía
Editors: Bianca Beks, G. Michael Listman, Julie Mollins, Geneviève Renard