Effect of Cover Crop Species and Termination Strategies on Corn and Soybean Growth and Development.

The benefits and challenges of using cover crops in agricultural production systems are often discussed anecdotally; however, research evaluating the management practices associated with cover crops is sparse. The objective of this study was to evaluate how multiple cover crop species and multiple termination strategies effect weed suppression and crop growth in a corn and soybean production system. Five winter annual cover crop treatments (cereal rye, hairy vetch, radish, three-way combination, and check) were selected to represent the most common cover crop species grown in Nebraska. Four termination strategies (early chemical termination, mechanical removal, roller/crimper, and green planting followed by chemical termination) were selected to eliminate the cover crops in the spring. Corn and soybeans were planted into each treatment and percent ground cover was determined at two, three and four weeks after planting using the Canopeo mobile application developed by Oklahoma State University. The study was conducted near Mead, NE in a RCBD with 5 replications. Cover crops were planted in September of 2015 and crops were planted in May of 2016. Early percent ground cover measurements indicated that there was substantial competition due to living cover crops and weed pressure. Later percent ground cover measurements were indicative of the crop stand and crop vigor in each plot. The results of this experiment indicate that both the cover crop species and termination strategy used can have a substantial impact on weed suppression and crop emergence and growth. The study will be conducted again in 2016/2017. Further studies are needed to refine the recommendations given to growers on how to terminate cover crops in a corn and soybean production system.