Most farm fields in the U.S. Midwest lay bare over the winter. From the time of corn and soybean harvests—sometime between September and December—until the planting season in spring, valuable topsoil is often unprotected.
Most farm fields in the U.S. Midwest lay bare over the winter. From the time of corn and soybean harvests—sometime between September and December—until the planting season in spring, valuable topsoil is often unprotected. Wind, snowmelt, and rain can remove topsoil and nutrients from fields and carry them into the Mississippi River, where, instead of providing a foundation for crop production, they contribute to water pollution and flow into the Gulf of Mexico.
Cover crops are increasingly planted by farmers between growing seasons to reduce soil erosion and fertilizer runoff. Planting cover crops has been found to protect soil, improve soil carbon sequestration, reduce nitrogen and phosphorous runoff, and reduce the need for chemical weed control. But the practice has hindered yields of primary cash crops, a recent study has found. The study, led by NASA Harvest researchers, analyzed the productivity of farm fields across the U.S. Midwest and found that cover crop adoption was associated with an average yield hit of 5.5 percent for corn fields and 3.5 percent for soybean fields.
The map shows the yield impacts for cover crop adoption for corn (maize) fields in 2019 and 2020 in six states: Iowa, Indiana, Missouri, Ohio, Illinois, and Michigan. Red and orange areas on the map show fields with yield reductions in response to cover crop adoption. Yields were reduced the most in dark red areas.
Read more at: NASA Earth Observatory
Photo Credit: Joshua Stevens, NASA Earth Observatory