Assessing the impacts of tillage and fertilization management on nitrous oxide emissions in a cornfield using the DNDC model

Abstract

AbstractQuantification and prediction of N2O emissions from croplands under different agricultural management practices are vital for sustainable agriculture and climate change mitigation. We simulated N2O emissions under tillage and no‐tillage,and different nitrogen (N) fertilizer types and application methods (i.e., nitrification inhibitor, chicken manure, and split applications) in a cornfield using the DeNitrification‐DeComposition (DNDC) model. The model was parameterized with field experimental data collected in Nashville, Tennessee, under various agricultural management treatments and run for a short term (3 years) and a long term (100 years). Results showed that the DNDC model could adequately simulate N2O emissions as well as soil properties under different agricultural management practices. The modeled emissions of N2O significantly increased by 35% with tillage, and decreased by 24% with the use of nitrification inhibitor, compared with no‐tillage and normal N fertilization. Chicken manure amendment and split applications of N fertilizer had minor impact on N2O emission in a short term, but over a long term (100 years) the treatments significantly altered N2O emission (+35%, −10%, respectively). Sensitivity analysis showed that N2O emission was sensitive to mean annual precipitation, mean annual temperature, soil organic carbon, and the amount of total N fertilizer application. Our model results provide valuable information for determining agricultural best management practice to maintain highly productive corn yield while reducing greenhouse gas emissions.