Cover Crop Effects on Nutrient Cycling and Microbial Communities.

Promotion of soil health in recent years has led to a renewed interest in cover crop use. Our objective was to measure the impact of cover crops on nutrient cycling and soil health parameters in a dryland cotton system. We evaluated the following cropping systems; 1) conventional tillage, 2) no-till, and no-till with the following cover crops 3) Austrian winter field pea, 4) hairy vetch, 5) crimson clover, 6) winter wheat, and 7) mixed legume/grass mix. Soil organic carbon, inorganic N, and Mehlich III P were quantified in the spring and fall each year. Following cover crop termination, phospholipid fatty acid analysis (PFLA) was used to quantify microbial diversity. Austria winter field pea and hairy vetch tended to show higher available soil nitrate shortly after termination. These legume species also showed positive trends in increasing bacterial and fungi biomass. All treatments showed an improving trend for microbial measurements compared to the conventional tillage treatment.