Innovative irrigation system could future-proof India’s major cereals
This blog by the Thomason Reuters Foundation describes a study that demonstrated how rice and wheat can be grown using 40 percent less water through an innovative combination of existing irrigation and cropping techniques. Rice-wheat farming systems dominate India’s agriculture, providing 75 percent of national food grain production. Traditional management of these two crops is no longer sustainable. Conventional flood irrigation consumes vast quantities of water and energy, is labor-intensive, and can deteriorate soil health. Overuse of nitrogen-based fertilizers can pollute waterways and emit harmful greenhouse gases that cause climate change. There has been little understanding of the best way to design an irrigation network that can work for both rice and wheat crops with no modifications between rotations. Researchers tested eight combinations of promising techniques over a two-year period to understand which methods could help farmers save water and money. Rice and wheat grown using a sub-surface drip fertigation system, combined with conservation agriculture approaches — zero till, retaining residues on soil surface and dry seeding — used at least 40 percent less water than flood irrigation for the same amount of yields, and is still cost-effective for farmers. Further, both rice and wheat needed 20 percent less nitrogen-based fertilizer under the system to obtain grain yields similar to that under flood-irrigated crops, which could improve ecosystem health and cut greenhouse gas emissions. To make sure the system gets adopted, government subsidies are important drivers for agricultural technology adoption. More efforts are also needed to promote conservation agriculture even though India’s rice-wheat farmers have made great strides in implementing these practices over the past two decades.
The study that this blog is based on can be purchased here.