Career Award Supports Sustainable Rice Farming Work
Benjamin Runkle, assistant professor of biological and agricultural engineering, has received a $500,199 Faculty Early Career Development award from the National Science Foundation to expand his research on sustainable rice production.
Runkle works with several farmers in the Delta region of Arkansas to develop and test alternative irrigation strategies for rice production. Together they are trying to reduce the quantity of water used, which in turn decreases the amount of methane produced in flooded rice fields. They are attemping to do this without decreasing rice production, and in some cases they expect to actually increase crop yields.
Rice is a staple food for more than 3 billion people worldwide, and Arkansas is the top American rice producer. However, current rice farming methods, which involve keeping rice fields flooded with water, have a high environmental impact. Rice production consumes significant water resources and accounts for roughly 10 percent of humans’ overall methane emissions into the atmosphere. Methane is a more potent greenhouse gas than carbon dioxide.
“We hope that this project will expand sustainable rice production by validating recent conservation incentive programs that have supported alternative irrigation practices in more than 40,000 acres of rice fields in Arkansas,” Runkle said. “By fine-tuning these practices we hope to make them more accessible across the mid-South.”
The NSF award will enable Runkle to quantify the climate impact of these water-saving irrigation strategies. Rather than the traditional paddy style of rice farming, which involves flooding the field, one new strategy focuses on irrigating and drying the furrows between rows of rice plants. Another strategy uses plastic piping with multiple inlets to more efficiently irrigate fields. In addition to saving water, these practices deliver oxygen into the soil, which both prevents microbes from producing methane and inhibits their growth, thus significantly reducing methane emissions from the field. Additionally, with this practice, less carbon dioxide is produced, because by saving water, less energy is used by the pumps that pull groundwater from the aquifers for irrigation.
One of the problems of current rice farming methods is uncertainty about the exact amount of greenhouse gases emitted through the various stages of production. Runkle’s team will measure these critical emissions to establish baselines for comparison to emissions from more sustainable methods.
This project will inform policy and investment decisions in Arkansas and the mid-South. The findings will help farmers transition from conservation programs based solely on water savings to programs that integrate water conservation with greenhouse gas emission credits. These credits are facilitated by a public-private partnership between the U.S. Department of Agriculture’s Natural Resources Conservation Service and Terra Global Capital.
For his rice-farming research, Runkle has received funding from Arkansas Water Resources Center and the U.S. Geological Survey’s 104B grant program, which provides “seed” grants to gather pilot data that can be used for larger grant proposals. His work is also supported by the Natural Resources Conservation Service.