Effect of Cover Crop Species on Crop Yield and Soil Health in the Southeastern United States.

Cover cropping is a promising agroecosystem management practice as it provides a suite of soil and environmental benefits. Ample information is available on the general benefits of cover cropping including erosion prevention, weed suppression, water conservation and nutrient cycling. More local and regional data is necessary to determine the best cover cropping strategies that support sustainable crop production. Most importantly, comprehensive studies on the effectiveness of a mixture of cover crop (CC) species versus single or double CC species are limited. In this study, we evaluated the effect of a suite of CC species planted in a corn-soybean rotation experiment over a 3 year period at the University of Tennessee’s Research and Education Center in Milan, TN. The CC treatments include no cover, wheat, cereal rye, cereal rye plus crimson clover, cereal rye plus hairy vetch and the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS) soil health mixture (SHM) which is a combination of cereal rye, whole oats, purple top turnips, daikon radish, crimson clover and Austrian winter pea. Soil samples were collected in October 2016 at a depth of 0-15 cm and the crop yield data were recorded. Results showed an increase in soybean yield after 3 years of SHM treatment, but no increase in corn yield. The SHM treatment also showed an increase in soil moisture content. Soil organic carbon and total nitrogen content did not change across the CC treatments. However, the combination of cereal rye and hairy vetch and the SHM treatments showed an increase in inorganic nitrogen content. Overall, the SHM treatment showed promising results to enhance soil quality and crop yield as compared to other treatments. Multiple years of data will be collected to obtain confirmatory evidence on the role of CC species on agroecosystem sustainability in the southeast US.