T.C. Kaspar and M.G. Bakker
Corn and soybean farmers in the upper Midwest are showing increasing interest in winter cover crops. Cover crops can improve the sustainability and resilience of corn and soybean production systems. At present, the most widely used cover crops in corn-soybean systems in the upper Midwest have been winter cereals. However, there have been isolated reports of corn yield reductions following winter rye cover crops and the risk of corn yield reductions will reduce the likelihood of farmers adopting cover crops. Although there are many possible causes of corn yield reductions following winter cereal cover crops, we suspect that there may be differences among winter cereal species or cultivars in their effect on corn yield. To test this idea seven winter rye cultivars, two winter triticale cultivars, and three winter wheat cultivars were planted following soybean harvest in four years to determine their effect on the following corn crop. We found that the twelve cultivars differed in growth and nitrogen uptake over the four years. Additionally, the winter cover crops reduced corn yield in only two of the four years, but two winter rye cultivars had no effect on corn yield in either year. This research shows that there are differences in cover crop growth and their impact on yield of the following corn crop among winter cereal cultivars. In the future we may be able to select or breed for winter cereal cover crops that have a greater potential for shoot growth and also have a lower risk of negatively affecting corn yield. Reducing the risk of yield losses and increasing cover crop growth will increase adoption of cover crops, which will improve the sustainability of cropping systems.
Article Citation: Kaspar, T.C., and M.G. Bakker. 2015. Biomass production of 12 winter cereal cover crop cultivars and their effect on subsequent no-till corn yield. J. Soil Water Conserv. 70:353-364.
Journal of Soil and Water Conservation article here.