Getting Legume Cover Crops to Work in Mid-Atlantic Crop Rotations

Abstract

In the mid-Atlantic United States, legume cover crop adoption is limited by the shortened establishment window after double-crop soybean (Glycine max (L.) Merr.) harvest. Interseeding legume cover crops into wide-row (76 cm) double-crop soybean presents an opportunity to supplement inorganic nitrogen (N) fertilizer in the subsequent corn (Zea mays L.) crop. We conducted field trials in Maryland and Delaware in which mixtures of cereal rye (Secale cereale L.) + hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), red clover (Trifolium pratense L.), or winter pea (Pisum sativum var. arvense (L.) Poir) were interseeded into double-crop soybean. We then examined the N contributions of the cover crop mixtures in combination with sidedress applications of inorganic N fertilizer on corn yields in Maryland in 2018 and 2019. This research demonstrated that interseeding cover crops into double-crop soybean is a potential strategy for increasing regional adoption of legume cover crops.