Intensifying winter rye cover crop management via fertilization and harvesting: Five‐year insights from the western US Corn Belt

Abstract Intensifying cover crop (CC) management via fertilization and harvesting could be a strategy to enhance agroecosystem benefits of CCs. Fertilization may boost productivity in low‐biomass producing CCs (e.g., winter CCs) and allow for biomass harvest to support livestock and other off‐farm uses while still delivering other soil services. We studied the impact of winter rye ( Secale cereale L.) CC fertilization (0, 50, and 100 kg N ha −1 ) and CC harvesting on aboveground and belowground CC biomass production, soil organic matter, soil nitrate, and crop yields under irrigated no‐till corn ( Zea mays L.)–soybean ( Glycine max L.) in the western US Corn Belt for 5 years. Fertilization increased aboveground CC biomass production in 2 of the 5 years. Across both of those 2 years, CC biomass production increased by 0.68 Mg ha −1 under 50 kg N ha −1 and by 1.15 Mg ha −1 under 100 kg N ha −1 over no fertilization, indicating that the increase in biomass production with fertilization was relatively modest. CC harvesting increased biomass production by 0.36 Mg ha −1 in 2 of 5 years. Fertilization did not affect forage CC nutritive value parameters, although numerically these parameters tended to increase. Fertilization increased soil nitrate concentration by 29%–53% at some soil depth intervals in the 60‐cm depth. Fertilization and harvesting did not affect CC root biomass production, soil organic matter concentration, or crop yields. Overall, N fertilization of winter rye CCs may not increase CC biomass production in most years in this temperate soil.