Investigating tradeoffs in nitrogen loss pathways using an environmental damage cost framework

Abstract

AbstractFew studies have addressed whether in‐field practices to reduce nitrate‐nitrogen (NO3‐N) leaching might increase nitrous oxide (N2O) emissions, which could undermine attempts to mitigate agricultural N pollution. Over a 3‐year period, we assessed the impacts of N application timing and cereal rye (Secale cereale L.) cover crop on subsurface drainage NO3‐N leaching and N2O emissions to quantify changes in total N loss and corresponding social and environmental damage costs under continuous corn (Zea mays L.). While NO3‐N losses were reduced by 37% with the combination of in‐season split N application and cereal rye cover crop relative to pre‐season N application, soil N2O emissions increased by 26%, highlighting a tradeoff between N loss pathways. As a result, total N losses and social and environmental damage costs from each system were not different. These results demonstrate the importance of addressing agricultural N pollution using a holistic framework accounting for the environmental and social risks of both NO3‐N losses and N2O emissions.