Greenhouse gas (GHG) emissions from agricultural soils are affected by various environmental factors and agronomic practices. The impact of inorganic nitrogen (N) fertilization rates and timing, and water table management practices on N₂O and CO₂ emissions were investigated to propose mitigation and adaptation efforts based on simulated results founded on field data. Drawing on 2012–2015 data measured on a subsurface-drained corn (Zea mays L.) field in Southern Quebec, the Root Zone Water Quality Model 2 (RZWQM2) was calibrated and validated for the estimation of N₂O and CO₂ emissions under free drainage (FD) and controlled drainage with sub-irrigation (CD-SI). Long term simulation from 1971 to 2000 suggested that the optimal N fertilization should be in the range of 125 to 175 kg N ha⁻¹ to obtain higher NUE (nitrogen use efficiency, 7–14%) and lower N₂O emission (8–22%), compared to 200 kg N ha⁻¹ for corn-soybean rotation (CS). While remaining crop yields, splitting N application would potentially decrease total N₂O emissions by 11.0%. Due to higher soil moisture and lower soil O₂ under CD-SI, CO₂ emissions declined by 6% while N₂O emissions increased by 21% compared to FD. The CS system reduced CO₂ and N₂O emissions by 18.8% and 20.7%, respectively, when compared with continuous corn production. This study concludes that RZWQM2 model is capable of predicting GHG emissions, and GHG emissions from agriculture can be mitigated using agronomic management.

农业土壤中的温室气体（GHG）排放受到各种环境因素和农艺实践的影响。研究了无机氮（N）的施肥速率和施肥时间以及地下水位管理措施对N ₂ O和CO ₂排放的影响，并根据基于实地数据的模拟结果提出了缓解措施和适应措施。利用在魁北克南部的地下排水玉米田（Zea mays L.）上测得的2012-2015年数据，对根区水质模型2（RZWQM2）进行了校准和验证，以估算N ₂ O和CO ₂自由排水（FD）和分灌溉控制排水（CD-SI）下的排放。1971年至2000年的长期模拟表明，最佳氮肥施用量应在125至175 kg N ha ^-1范围内，以获得更高的NUE（氮利用效率，7–14％）和更低的N ₂ O排放（8– 22％），而玉米-大豆轮换（CS）则为200 kg N ha ^-1。在保持作物单产的同时，氮肥的分配可能会使N ₂ O的总排放量减少11.0％。由于CD-SI下较高的土壤湿度和较低的土壤O ₂，与FD相比，CO ₂排放量减少了6％，而N ₂ O排放量却增加了21％。CS系统减少了CO ₂与连续玉米生产相比，N ₂ O排放量分别减少了18.8％和20.7％。这项研究得出的结论是，RZWQM2模型能够预测温室气体排放，并且可以通过农艺管理减轻农业的温室气体排放。