Effect of Soybean Maturity on Establishment of Cover Crops in Missouri.

Earlier establishment of cover crops following soybean (Glycine max [L.] Merr.) could help reduce erosion, increase forage opportunities, and suppress winter annual weeds. The objective of this research was to evaluate the effect of soybean maturity group on the establishment of turnip, annual ryegrass, winter rye, and collards and the subsequent impact on corn yields. Research was conducted from over four years at the University of Missouri Greenley Research Center near Novelty. A mid-group 2, 3, and group 4 soybean cultivar was harvested 18 Sep.-4 Oct., 28 Sep.-25 Oct., and 2 Oct.-25 Oct., respectively, which allowed earlier establishment of cover crops. However, soybean grain yields of the group 2 soybean cultivar was 13% lower than the group 4 cultivar. Cover crop biomass yields were greatest following the group 2 soybean followed by the group 3 and group 4 cultivar. Corn grain yields following annual ryegrass was similar to the non-cover crop control, but yields following winter rye were 17% lower than the non-cover crop control.