Cover crops improve long-term soil health

COLUMBIA, Mo.–Decades of cover crop research is beginning to pay off.

University of Missouri Extension and the USDA Agricultural Research Service have used cover crops in a corn-soybean-wheat rotation at a farm near Centralia, Missouri, since 1991. Newell Kitchen, an ARS soil scientist and MU Extension associate professor, says they have accumulated enough data to fully explore the benefits and possibilities of cover crops.

“In 2012, it was a really hot year, a dry year, and cover crops helped keep soil temperatures down,” Kitchen says. “We were able to preserve soil moisture a little bit longer and saw a two to three bushel per acre increase in soybeans because of that.”

With 20 years of continuous cover crop research, Kitchen says they can compare conventional cropping systems with and without cover crops.

“We see better soil quality with cover crops on corn and soybean fields that are tilled as well as no-till,” Kitchen says. “You get a benefit by taking away tillage, but there is a much greater benefit by including cover crops with no-till.”

Before ARS began the research, there were very few earthworms on the Centralia farm. Cover crops changed that.

“As strange as it sounds, earthworms are a good indicator of soil health,” Kitchen says. “The more worms you have, the better the soil. And with cover crops we see this type of improved soil health.”

Cover crops reduce runoff, preventing erosion and improving organic matter and soil stability.

“We are still working on management of cover crops affecting grain yields,” Kitchen says. “But there are some tremendous ecological benefits from using cover crops. They may have an important role for sustaining agricultural soils as we go forward.”