中文摘要：

由于冬季气温低,温室气体的排放往往被忽视.而最新研究结果显示,土壤冬季仍然持续排放N2O.研究不同土地利用方式下冬季N2O排放规律对于评估农田土壤N2O排放有重要意义.在中国科学院桃源农业生态试验站选择4种不同的土地利用方式包括冬闲稻田、油菜地、蜜柚园和撂荒地,采用静态箱采集和气相色谱法结合监测N2O排放动态.结果表明,冬闲稻田和油菜地N2O排放量明显高于蜜柚园和撂荒地,其顺序为：油菜地〉冬闲稻田〉蜜柚园〉荒地.N2O的累积排放量分别为0.502、0.392、0.162、0.075 kg·hm-2.冬闲稻田和油菜地的累计排放量占全年排放量的贡献较大而蜜柚园和荒地则较小.相关性分析结果表明,对于不同的土地利用方式,当土壤温度〉5℃时,冬季N2O排放通量与土壤温度都有显著指数正相关,而与水分没有相关性.本研究表明,当土壤温度〉5℃,土壤温度是冬季桃源不同土地类型N2O排放的主导因素;当土壤温度〈5℃时,土壤温度和其他环境因素综合影响了N2O的排放.

英文摘要：

Due to the low temperature in winter,the emissions of greenhouse gas are often neglected.And the latest research results showed that there is continuous N2O emission in winter,therefore,research on understanding the N2O flux regulation is important for evaluating agricultural soil N2O emission.By using static chamber techniques,the N2O emission from soils under different land use patterns including fallow paddy field,rape cropping,honey pomelo orchard and abandon land in Taoyuan agricultural ecological experimental station of Chinese Academy of Sciences was measured.The results showed that fallow paddy field and rape cropping N2O emissions were obviously higher than those of the honey pomelo orchard and abandon land,and the total N2O flux in winter decreased in the order of rape croppingfallow paddy fieldhoney pomelo orchardabandon land.Cumulative N2O emission was 0.502,0.392,0.162 and 0.075kg·hm-2,respectively.Fallow paddy field and rape cropping N2O emissions accounted for large proportions of the annual N2O emissions,while honey pomelo orchard and abandon land had small contribution to the annual N2O emissions.The correlation analysis results showed that for different land use patterns,when the soil temperature 5℃,N2O emissions in winter and soil temperature had significant positive exponential correlation,and had little to do with moisture.This research showed that： when the soil temperature 5℃,the soil temperature was the leading factor in N2O emissions in winter under different land patterns;When the soil temperature 5℃,other environmental factors had comprehensive influences on the N2O emissions.