No-burn farming strategy to cut air pollution over Delhi
doi:10.1038/nindia.2019.110 Published online 13 August 2019
Burning agricultural fields to dispose of crop residue after harvesting – a practice widespread in north-west India – has been blamed for negatively affecting the region’s air quality and the health of its people. An international team of researchers, including from India, say this practice may end if farmers are encouraged to use a new seeder that offers a no-burn farming strategy1.
Eighty per cent of agriculture in the north-western Indo-Gangetic plains is based on a rice-wheat cropping system. After mechanically harvesting rice, farmers have different options for sowing wheat (the next crop) but – in the absence of profitable alternatives – most of the 2.5 million farmers choose to burn the rice straw, before sowing wheat using conventional seeders.
The researchers say their "Happy Seeder" can end this practice. Propelled by a tractor, it cuts and lifts rice straw, sows wheat directly into the soil, and deposits the cut straw as mulch over the sown area.
After evaluating the costs and benefits of 10 different farming options, the researchers found that the seeder could lead to an almost 10 per cent increase in farmer profits, eliminate air pollution from burning, and lower agriculture’s contribution to India’s greenhouse gas emissions by about 18 per cent.
The report says half of the rice-wheat cropped area will require about 16,000 such seeder machines, meaning a required investment of about 2.4 billion rupees (US$34.5 million), which is less than one-quarter of the government subsidy currently allocated for residue management. The full-scale adoption of the seeder would require additional private-sector contributions.
"Farmers need support and a clear and predictable framework to make the switch to no-burn alternatives," Priya Shyamsundar, of The Nature Conservancy in Washington, DC, and lead author said.
1. Shyamsundar, P. et al. Fields on fire: Alternatives to crop residue burning in India. Science 365, 536-538 (2019) doi: 10.1126/science.aaw4085