Simulate the Effects of Residue Removal and Nitrogen Application on Nitrous Oxide and Carbon Dioxide Emissions in Biomass Sorghum Production.

Management practices including residue removal and nitrogen (N) application may impact biomass sorghum production and greenhouse gas emissions. In this study a processed-based model, DNDC, was used to simulate the effects of residue removal and N fertilization on nitrous oxide (N₂O) and carbon dioxide (CO₂) emissions in the Southcentral USA. The experimental results indicated that residue removal and N application affected nitrous oxide and carbon dioxide emissions. The model predictions were close or within the range of uncertainty of estimates derived from measurements. After being well calibrated by one randomly selected measurement, the DNDC model was able to predict main impacts of residue removal and N fertilization on nitrous oxide and carbon dioxide emissions, although some inconsistence during model verification were observed which is partially due to the field sampling variation. The projected long-term changes in nitrous oxide and carbon dioxide indicated that residue management and N rate are important in decreasing greenhouse gas emissions.