USDA Report: Cover Crops Delivered Benefits Amid Drought
Though little precipitation fell from the clouds last summer across central Ohio, David Brandt’s healthy soil delivered what the sky could not—moisture to his thirsty crops.
At harvest time, while other farmers in the area averaged only 60-70 bushels of corn per acre, Brandt’s yield was nearly twice that. He attributes the difference to the health and vitality of his soil — and his use of cover crops.
The results from a recent survey confirm that soil health-building cover crops delivered for many others affected by the drought, too.
More than 750 farmers, primarily from the drought-stricken upper Mississippi River watershed, responded last winter to a survey conducted by the USDA North Central Region Sustainable Agriculture Research and Education program and the Conservation Technology Information Center.
While average yield differences reported were not as dramatic as those experienced by Brandt — who has been farming with cover crops and other soil health-improving techniques for decades — farmers who planted corn after cover crops had a 9.6 percent increase in yield compared to side-by-side fields with no cover crops. Likewise, soybean yields were improved 11.6 percent following cover crops, according to the survey.
In the hardest hit drought areas of the Corn Belt, yield differences were even larger, with cover crop-growing farmers reporting an 11 percent yield increase for corn and a 14.3 percent increase for soybeans.
Soil health experts from USDA’s Natural Resources Conservation Service hope the results from this survey will underscore one important on-farm benefit of soil health-building cover crops: weather resiliency.
Yield improvements reflected in the survey can be attributed to better rooting of the cash crop, along with reduced soil moisture loss through evaporation, said David Lamm, NRCS soil health expert. “In addition to reducing soil moisture loss through evaporation, the residue blanket of the cover crops likely lowered soil temperatures, too, reducing plant stress,” he said.
“Where cover crops have been used for several years, organic matter typically increases, improving soil aggregation, allowing better rainfall infiltration and improving soil water-holding capacity,” Lamm said. “That additional water infiltration capacity is also helpful in extreme rainfall events — reducing erosion and mitigating the potential downstream flooding,” he said.
Through its “Unlock the Secrets in the Soil” campaign, NRCS is helping America’s farmers adopt soil health management systems, including the use of cover crops as appropriate, to help the nation’s farmers improve soil health on their land.
According to Lamm, weather resiliency is just one of the many benefits farmers will harvest through improved soil health. “Farmers practicing healthy soil methods have expenses that are lower, yields that are similar or higher, and environmental impacts on soil, water, air and wildlife that are minimal or beneficial,” he said.
Lamm said the specifics of a robust healthy soil system vary from farm to farm and state to state, but they all share four core principles. “To build the health of the soil, farmers need to minimize soil disturbance, energize with diversity, keep the soil covered and maximize living roots,” he said.
“All four principles build soil structure and the biological communities that feed and water crops and other plants,” Lamm said. “And three of those four principles are applied through the use of cover crops, which is exactly what Mr. Brandt and other soil health farmers are doing so successfully.”
Lamm said farmers interested in learning more about soil health-building cover crops and soil health management systems should contact their local NRCS office or visit www.nrcs.usda.gov.