中文摘要：

在句容水库农业流域的水塘和河流中,用密闭箱法于2007年8、11月和2008年2、5月采集水体表面排放的N2O气样,研究水塘和河流N2O排放速率的季节变化及其影响因素.结果显示,水塘N2O的排放速率范围在-0.42～16.76μg.m-.2h-1之间,河流N2O排放速率在0.29～8.41μg.m-.2h-1之间.由于降雪后冻融过程的影响,水塘和河流N2O排放速率在2月份达到最大值.流域内水塘和河流N2O总排放速率为118.4kg.a-1,农业流域水塘和河流是N2O的重要排放源.

英文摘要：

N2O gas samples were collected from the pond and river water surface in the agricultural watershed of Jurong reservoir,Jiangsu Province during August 2007 and May 2008.The seasonal variations in N2O flux emitting from these water bodies and their impact factors were analyzed.The results showed that N2O emission fluxes ranged from-0.42 to 16.76 μg·m-2·h-1 for ponds and from 0.29 to 8.41 μg·m-2·h-1 for rivers.Ambient temperature affected N2O emission significantly,with the largest emission in February due to the water freeze-thaw after snowing.The flux of total N2O emission from ponds and rivers was 118.4 kg·a-1,indicating that ponds and rivers were important sources of N2O emission.