Cover Crop Biomass Production and Effects on Soil Moisture in the Upstate of South Carolina

Cover crops can protect soil health and increase climate resilience of the crop production systems. However, few agronomic crop producers in the southern USA currently use them. Constraints on producer use of cover crops in this region include, lack of knowledge regarding the best cover crops for their locality and cropping system and potential impacts on plant-available soil moisture along with concerns about the cost and labor associated with cover cropping. The present research evaluated biomass production, soil moisture retention, and water use efficiency of single species and multi-species fall-winter cover crops in South Carolina. Overall, a mixture of Austrian winter pea, rye, crimson clover, hairy vetch, and oats and single species of rye were the best, single species of crimson clover was the worst, and a mixture of crimson clover and rye, a mixture of oats, wheat, crimson clover, radish, and turnip, and a mixture of oat and radish were the intermediate type of cover crops based on the parameters evaluated in this study. None of the cover crops depleted soil moisture greater than the fallow treatments: a weed-free fallow maintained through herbicide application and a weedy fallow (no herbicide application). Our results do not support the farmer concern, whether cover crop water use reduces available soil moisture for the subsequent cash crop, more than what a fallow does. Future studies are warranted to evaluate the effect of the single species and multispecies (grass, legume, and/or brassica combinations) cover crops on soil health in South Carolina