Intersowing Cover Crops into Standing Soybean to Reduce Soil Loss in Late Fall.

In order to reduce soil erosion in the northern Great Plains following soybean [Glycine max (L.) Merr.], which leaves the soil exposed to the elements, cover crops can be intersown into standing soybean. The objective of this study was to determine cover crop biomass yield and cover, intersown at two soybean reproductive stages R4 and R6, as well as any impacts on soybean yield. This experiment was conducted at two locations, Fargo and Prosper, ND, in 2016. The experimental design was a RCBD with four replicates, in a split-plot arrangement where soybean reproductive stage was the main plot and cover crop treatment was the sub-plot. Four cover crops, winter camelina (Camelina sativa L.) cv. Joelle, Austrian winter pea (Pisum sativum ssp. arvense (L.) Poir), winter rye (Secale cereal L.) cv. Rhymin, and forage radish (Raphanus sativus L.) cv. Daikon, were sown into the ground at the R4 and R6 stage of soybean. Results indicate that soybean yield and quality were not affected by intersowing cover crops. At both locations, Austrian winter pea and winter rye produced greater biomass than winter camelina and forage radish. Intersowing cover crops at later soybean reproductive stages shows to be a viable solution to mitigate soil erosion in areas that have shorter growing seasons. Further research is needed to find the correct cover crops that maximize growth while growing under the soybean canopy.