This experiment studied the ammonia volatilization and N2O emissions from the winter wheat-summer maize rotation system in North China Plain using continuous air flow enclosure method. The results showed that the ammonia volatilization and N2O emissions varied seasonally, increased with N fertilization rate, and the peak emission appeared 1-3 days after fertilization. Higher ammonia volatilization and N2O emissions from maize season than those from wheat were found, which contributed to 53.5%-68.9% and 54.7%-82.3% of the total losses, respectively. In the wheat-maize rotation system, the net loss of ammonia volatilization were 4.28-31.31 kg N-hm-2, accounting for 3.17%-5.80% of the N fertilization rate respectively; Meanwhile, the net N2O emissions were 50.95-1051.03 g Nhm-2, accounting for 0.04%-0.23 % of the N fertilization rate. Consequently, the major factor influencing gaseous loss in wheat-maize rotation system was the N fertilization rate, and the key period to control gaseous losses was summer maize season.%试验采用密闭室间歇通气法研究华北平原冬小麦(Triticum aestivum Linneaus)-夏玉米(Zea mays Linneaus)轮作体系在不同施氮水平下农田氨挥发和N2O排放.结果表明:冬小麦季和夏玉米季的氨挥发速率与N2O排放通量呈现出季节性动态变化,且随着施氮量的增加而增加,均在施肥后第2～3天出现峰值.玉米季氨挥发量和N2O排放量均高于小麦季,分别占整个轮作周期气态损失的53.5％～68.9％和54.7％～82.3％.轮作体系中氨挥发净损失量(以N计)为4.28～31.31 kg·hm-2,占施氮量的3.17％～5.80％;N2O净排放损失量(以N计)为50.95～1051.03 g·hm-2,占施氮量的比例为0.04％～0.23％.因此,施氮量是影响冬小麦-夏玉米轮作体系气态损失重要因素,且夏玉米季是控制控制气态损失的关键时期.
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