Effect of Cover Crop and Crop Rotation on Soil Carbon, Nitrogen and Microbial Activity.

Understanding C, N and microbial dynamics in cropping systems with cover crops is valuable from both an economic and environmental perspective. An 11-year experiment evaluating cover crops starting in 2003 was conducted in the prairie region of west-central Indiana and included a corn (Zea mays L.) and soybean (Glycine max L.) rotation and a corn, soybean and wheat (Triticum aestivum L.) rotation. Initially, annual ryegrass (Lolium multiflorum Lam.) was the sole cover crop and in 2012, oilseed radish (Raphanus sativus L.) and hairy vetch (Vicia villosa Roth) were added. Grain yield was recorded yearly and total C and N, mineralizable C and N, microbial biomass C, and soil enzyme activity were recorded intermittently. The poster that follows will highlight some insights from this study.