Upland croplands are the main source of N2O emissions. Mitigation of N2O emissions from upland croplands will greatly contribute to an overall reduction of greenhouse gases from agriculture. Using 355 datasets extracted from 103 publications, a Meta-analysis was performed to investigate the mitigation options and potential of N2O emissions from wheat and maize fields in China. The results showed that application of inhibitors in wheat and maize fields reduced 36%?46% of the N2O emissions with an increase in crop yield. Cutting the application rates of nitrogen fertilizers by no more than 30% could reduce N2O emissions by 10%?18% without crop yield loss. Applications of slow (controlled-) release fertilizers and incorporations of crop residues could significantly mitigate N2O emissions from wheat fields, but the mitigation was not statistically significant in maize fields. The gross N2O emissions could be reduced by 9.29?13.90 Gg N2O-N per wheat season and 10.53?23.19 Gg N2O-N per maize season when different mitigation options were put into practices. The mitigation potential (MP) in wheat cultivation was particularly notable for Henan, Shandong, Hebei and Anhui provinces, accounting for 53% of the total MP in wheat fields. Heilongjiang, Jilin, Shandong, Hebei and Henan provinces showed high MP in maize cultivation, accounting for approximately 50% of the total MP in maize fields.%旱作农田是N2O的主要排放源,削减其N2O排放有助于整体降低农田温室气体排放.运用整合分析(Meta-analysis)的方法,研究了不同农业管理措施对中国小麦和玉米农田N2O排放的影响,并估算了各减排措施的减排潜力.结果表明:添加抑制剂可显著减少小麦和玉米农田N2O排放36%~46%,并增加作物产量;施氮量减少30%以内,可削减N2O排放10%~18%,且对产量无明显影响;施用缓(控)释肥和秸秆还田能显著减少小麦田N2O排放,但对玉米田的减排效果并不显著.在不同的减排措施下,中国小麦和玉米农田N2O减排潜力分别为9.29~13.90 Gg N2O-N/生长季和10.53~23.19 Gg N2O-N/生长季.河南、山东、河北和安徽省小麦田减排潜力最大,占全国小麦田N2O减排潜力的53%;黑龙江、吉林、山东、河北和河南省玉米田减排潜力最大,约占全国玉米田N2O减排潜力的50%.
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