中文摘要：

2005年6月-2006年6月利用静态箱／气相色谱法对成都平原水稻-油菜轮作系统氧化亚氮（N2O）排放进行定位观测，研究了该系统N2O排放特征及土壤水热状况、氮肥施用、作物参与对N2O排放的影响．结果表明：成都平原水稻-油菜轮作系统N2O排放总量为（8．3±2．8）kg·hm^-2·a^-1，水稻季、油菜季和休闲期对整个轮作周期N2O排放总量的贡献分别为30％、65％和5％．水稻季N2O平均排放速率表现为排灌交替期最大，持续淹水期和排水晒田期相当；氮肥施用是N2O排放高峰出现的主要驱动力；土壤表层含水量偏低是旱季出现土壤N2O吸收现象的主要原因．土壤水分、土壤温度、施用氮肥和作物参与均在不同程度上影响N2O排放，土壤水分是影响N2O排放的关键因子，避免水稻季土壤频繁干湿交替或控制旱季土壤水分（表层土壤含水孔隙率介于50％～70％）可有效抑制N2O排放．

英文摘要：

By using static chamber/gas chromatograph techniques, the N2O emission from ricerapeseed rotation system in Chengdu Plain of Sichuan Basin was measured from June 2O05 to June 2O06, with its characteristics and affecting factors investigated. The results showed that the total emission of N2O in a rotation cycle was （8. 3 ± 2.8 ） kg · hm^-2 · a^-1, and the emission in rice season, rapeseed season and fallow season accounted for 30% , 65% , and 5% of the total, respectively. In rice season, the mean N2O flux was higher during alternative drainage and irrigation than during continuous flooding and drainage, and was roughly the same during continuous flooding and drainage. N application was the main driving factor for the appearance of N2O emission peak, and the lower moisture content in surface soil layer in rapeseed season and fallow season was the main cause inducing soil N2O absorption. Soil moisture, soil temperature, N application, and crop involvement affected the N2O emission to various extents, and soil moisture was the key factor affecting the N2O emission. To avoid the high frequency of dry and wet alternation in rice season or to regulate soil moisture content to a level of 50%-70% WFPS （percentage of water-filled pore space） in rapeseed season and fallow season could effectively decrease the N2O emission from the rice-rapeseed rotation system.