ASHS 2024 Conference

Cover crops provide numerous ecological benefits to production systems. Maximizing these benefits requires identifying species and varieties that are the best fit both geographically and for the planting/termination time frame dictated by the accompanying cash crop system. In 2019, the University of Tennessee began a cover crop variety trial to help growers make better informed decisions on which of a broad range of cover crop species and varieties worked best in their specific region and production system. In fall 2022, in collaboration with the Southern Cover Crops Council, this trial was expanded to cover a 10-state region of the Southern US (TN, FL, NC, KY, VA, SC, TX, GA, AR, and AL) and became known as the Southern Cover Crop Variety Trial. This trial program is currently in its second year, with each trial year running from fall through the following spring. Trial sites were planted in mid-October each year. Cover crop cover, weed suppression, height, biomass, and estimated nitrogen release were measured in early and late spring. Twenty entries each were evaluated in the 22-23 and 23-24 trial years. However, as a fee-based program, entries were submitted by public and private institutions and varied from year to year. Eleven of the twenty entries were evaluated in both trial years. In year one, top-performers by rank were largely uniform across sites, consisting primarily of cereal rye and hairy vetch varieties. Many clover species, particularly crimson clover, exhibited greater variation in performance ranking among locations. Performance values varied significantly among and within locations, species, and evaluation period. Data collection for year two will be completed in Spring 2023 and will be presented.