优化氮肥施用和秸秆还田技术为途径的农业管理措施被认为是提升农业可持续性的有效手段, 然而当前关于氮肥和秸秆还田对小麦产量和N₂O排放影响的研究仍十分有限。为此, 本研究基于2000—2022年发表的关于长江中下游流域氮肥和秸秆投入下小麦产量和N₂O排放变化的文献, 运用随机森林建模, 定量分析氮肥和秸秆还田对小麦产量和N₂O排放的影响, 并结合情景设置进行了特定地点的小麦产量和N₂O排放模拟, 同时评估了碳排放强度(CEE)和净生态系统经济效益(NEEB)。结果表明, 建立的区域尺度小麦产量与N₂O排放对氮秸互作响应的随机森林模型, 验证结果R²分别为0.66和0.65, RMSE分别为0.70和1.11。结果表明施氮量和土壤有机质是影响小麦产量和N₂O排放的重要因素。综合来看, 达到最大产量所需的氮肥量为208~212 kg hm^-2, 达到最小CEE所需的氮肥量为113~130 kg hm^-2, 达到最高的NEEB所需的氮肥量为202~205 kg hm^-2, 其中在6.75 t hm^-2的秸秆投入下施用202 kg hm^-2的氮肥可以获得最高的生态收益1.37万元。优化氮肥和秸秆投入具备减少作物碳排放强度并获得最大净生态环境效益的潜力。

The optimization of agricultural practices such as nitrogen and straw input may be an effective option for maintaining environmental sustainability. However, previous studies on the effects of nitrogen and straw inputs on wheat growth and N₂O emission reduction were limited. Therefore, the present study was based on the literature published from 2000 to 2022 about wheat yield and N₂O emissions under different nitrogen and straw inputs amendment in the middle and lower reaches of the Yangtze River, a random forest (RF) model of wheat yield and N₂O emission was constructed. And the influence of nitrogen and straw inputs on wheat yield and N₂O emissions was quantified. Based on the developed model, wheat yield and N₂O emission simulations at the experimental site were carried out in combination with scenario settings, and the carbon emission intensity (CEE) and net ecosystem economic benefits (NEEB) were evaluated. The results were as follow: On the regional scale, an RF model was established for the response of wheat yield and N₂O emission to the application of nitrogen fertilizer and straw returning. The verification results were R² of 0.66 and 0.65, and RMSE of 0.70 and 1.11, respectively. Quantifying the importance of independent variables showed that nitrogen application rate and soil organic matter were essential for yield and N₂O models. For nitrogen fertilizer and straw management under different targets, the amount of nitrogen fertilizer required to achieve the highest yield was 208-212 kg hm^-2, the amount of nitrogen fertilizer required to achieve the minimum CEE was 113-130 kg hm^-2, and the amount of nitrogen fertilizer required to achieve the highest NEEB was 202-205 kg hm^-2, of which the highest ecological benefit of 13,669.18 CHY could be obtained by applying 202 kg hm^-2 nitrogen fertilizer under the straw input of 6.75 t hm^-2. Our results indicate that optimizing nitrogen fertilizer and straw inputs has the potential to reduce crop carbon emission intensity and maximize net ecological and environmental benefits.