Winter rye cover crop management influences on soil water, soil nitrate, and corn development

A winter rye (Secale cereale L.) cover crop can be seeded after corn (Zea mays L.) silage to mitigate some of the environmental concerns associated with corn silage production. Rye can be managed as a cover crop by chemical termination or harvested for forage. A fi eld study was conducted in Morris, MN in 2008 and 2009 to determine the impact of killed vs. harvested rye cover crops on soil moisture and NO₃-N, and to monitor the impact of the rye on subsequent corn yield. Corn for silage was seeded either aft er winter fallow (control), aft er a rye cover crop terminated 3 to 4 wk before corn planting (killed rye), or aft erarye forage crop harvested no more than 2 d before corn planting (harvested rye). Soil moisture after killed rye was similar to the control, but aft er harvested rye was 16% lower. Available soil NO₃-N was decreased aft er both killed rye (35%) and harvestedrye (59%) compared to the control. Corn biomass yield aft er killed rye was similar to the control, but yield following harvestedrye was reduced by 4.5 Mg ha^-1. Total forage biomass yield (silage + rye) was similar for all treatments. This work demonstrates that the environmental benefits of a winter rye cover crop can be achieved without impacting corn yield, but the later termination required for rye forage production resulted in soil resource depletion and negatively impacted corn silage yield.