Parameterizing an agricultural production model for simulating nitrous oxide emissions in a wheat–maize system in the North China Plain

Concentrations of atmospheric nitrous oxide (N2O), a potent greenhouse gas, have been continuously increasing, and cropland soils are one of the largest sources of N2O. Variations in environmental and anthropogenic factors have substantial impacts on both the frequency and magnitude of N2O emissions. Based on measurements from a wheat–maize system in the North China Plain, the authors parameterized the Agricultural Production Systems Simulator (APSIM) model, which was initially developed in Australia, for simulating N2O emissions under different agricultural management practices. After calibrating one of the key parameters – the fraction of N2O lost in nitrification (k2) – the results showed that the model successfully captured the daily N2O fluxes under different nitrogen fertilization treatments, but underestimated some large peak fluxes. By pooling all data together, the calibrated APSIM model also performed well in representing cumulative N2O emissions under various treatments at annual and fi...