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

农田土壤是大气氧化亚氮的一个重要排放源,农田氧化亚氮的排放同时受到气候环境和人为活动的复杂影响。本文基于中国华北平原的一个农田试验站的观测数据,对农业生产模拟器(APSIM)进行参数化,并检验该模型在不同时间尺度上模拟农田氧化亚氮排放的能力。结果表明,对消化系数(k_2)进行校正后,模型能够较好地模拟不同时间尺度和不同施肥处理下小麦-玉米系统的土壤氧化亚氮排放,但是对于一些较高的峰值排放模拟效果欠佳。

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 finer （monthly and daily） time scales.