Integrating agricultural practices into TRIPLEX-GHG model for simulating global croplands nitrous oxide emissions

Abstract:

Nitrous oxide (N2O) from cropland is one of the most important greenhouse gases sources which is difficult to quantify at large-scale. To simulate the N2O emission from global croplands, the new version of process-based TRIPLEX-GHG model was developed by coupling the major agricultural activities. The coefficient of NO3- consumption rate for denitrification (COEdNO3) was found to be the most sensitive parameter based on the sensitivity analysis and was calibrated with field data from 39 sites observations across major croplands globally. The model performed well when simulating the magnitude of N2O emissions and was able to capture the temporal patterns of N2O emissions. The COEdNO3 ranged from 0.01 to 0.05 and the continent-mean of the parameter was used for model validation. The validation results indicated that the means of measured daily N2O fluxes during experiment periods are highly correlated with that of modelled results (R² = 0.87). Consequently, our model simulation results suggest that the new version of TRIPLEX-GHG model is reliable to simulate N2O emissions from various croplands at global scale.