Inverting Soil Decreases Arsenic and Improves Rice Yields

Superfund Research Program

Illustration of how soil inversion replaces high-arsenic soil with low-arsenic soil to increase rice yield. (From Huhmann B, Harvey CF, Uddin A, Choudhury I, Ahmed KM, Duxbury JM, Ellis T, van Geen A. 2019. Inversion of high-arsenic soil for improved rice yield in Bangladesh. Environ Sci Technol 53(7):3410-3418.)

By exchanging high-arsenic soil at the surface with deeper low-arsenic soil, researchers from the Columbia University Superfund Research Program (SRP) have demonstrated increased rice crop yields in Bangladesh. This approach, called soil inversion, increased rice yields 15 - 30% compared to plots that were not inverted. The team, led by Alexander van Geen, Ph.D., also reported that arsenic concentrations remained lower over four seasons of monitoring.

Arsenic contamination of water and food is associated with major environmental public health issues in the United States and around the world. Arsenic has been found in at least 1,149 of the 1,750 current and former National Priorities List sites identified by the U.S. Environmental Protection Agency.

In addition to health concerns, arsenic in soil can affect crop yield. Rice is the primary crop in Bangladesh, but yields are lowered due to the high concentration of arsenic in the top layer of soil from irrigation practices that rely on arsenic-contaminated groundwater. According to the authors, soil inversion may help reduce the negative effects of arsenic on rice yield, but long-term benefits may require using water from rivers or ponds that have lower arsenic content.