中文摘要：

田间采集的新鲜土壤样品分别在室温下风干（土样D）和淹水（土样S）保存110d后，将二者的含水量分别调至20％、40％、60％、80％、100％持水量（WHC，Water Holding Capacity），在25℃下培育138h，设置不通和通人10％（v／v）乙炔的处理。结果显示，在20％～80％WHC下培育时，土样S的氧化亚氮（N2O）排放量为土样D的2．48倍～6．36倍（P〈0．01），而在100％WHC水分含量下培育时，土样S的N2O排放量仅为土样D的19％（P〈0．01），通人乙炔不但未使土样D的N2O排放量增加，反而显著减少。通入乙炔的处理，培养结束后硝态氮的含量增加。随培育水分含量的升高，土样S和土样D的二氧化碳排放量增大。供试土样可能存在异养硝化作用。前期水分的差异显著影响土壤N2O排放量，故在田间测定土壤N2O排放量时，要考虑土壤前期水分的差异。

英文摘要：

A laboratory incubation experiment was conducted to investigate nitrous oxide （ N2O） emission from an arable Uhisol as affected by antecedent water regime. The soil was maintained either air-dried （Sample D） or submerged （Sample S） for 110 days before the two soil samples were adjusted in soil moisture up to or down to 20% , 40% , 60% , 80% and 100% water holding capacity （WHC） , respectively. And then they were incubated with or without 10% （v/v） acetylene for 138 h at 25℃. Results show N2O emission from Sample S was 2.48 to 6.36 times as much as that from Sample D with soil moisture content ranging from 20% to 80% WHC （p 〈0. 01 ）. When the soil moisture content was adjusted to 100% WHC, N2O emission from Sample S was only 19 percent of that from Sample D, and N2O emission from Sample D incubated with acetylene was lower than that without acetylene （p 〈 0.01 ）. The content of nitrate increased after incubation with acetylene. CO2 emission from Samples S and D increased with the soil moisture content. Heterotrophie nitrification might be present in the tested soil. Antecedent water regime significantly influences N2O emission, and should hence be considered as a factor in determination of N2O emission in situ.