May 31, 2018
Half of the world’s people, particularly in Asia, sub-Saharan Africa, Latin America and the Caribbean, depend heavily on one staple food crop: rice. Although rice is one of the world’s most important crops, it is also one of the most water intensive. For centuries, farmers have grown rice by flooding fields with fresh water, requiring more than two times the water needed for wheat or maize. We use a third of the world’s freshwater resources just to cultivate rice.
The flooding method may be its own worst enemy. Waterlogged soil in rice paddies creates the perfect home for microbes that release methane, a greenhouse gas more potent than carbon dioxide in trapping heat. By contributing 20 percent of the world’s man-made methane emissions, rice production helps drive climate change, which then threatens the water supply that sustains it.
Rimjhim Aggarwal, a Senior Sustainability Scientist at the Julie Ann Wrigley Global Institute of Sustainability at Arizona State University, is looking to transform the rice production process through a solar-powered drip irrigation technology developed by her partner, Jain Irrigation, Inc. The technology drips water slowly and directly into the rice plant’s roots, applying water in more precise amounts at strategic times rather than flooding the field entirely.
Without the flooded soil, methane-producing microbes cannot proliferate as easily, leading to reduced methane emissions. The process also reduces water consumption by 20 to 60 percent while increasing yields by 25 to 50 percent, making rice production more sustainable for both the environment and food security.