中文摘要：

以张家港市永联现代粮食生产基地为依托，选择两块试验田同步采集田面水和河道水，初步研究了南方集约型稻区水稻田面水、河道水中氮素变化规律。结果表明：①封闭的灌水河道具有积聚营养物质的作用，氮素浓度远高于田面水氮浓度，其中氨氮浓度甚至达到田面水氨氮浓度的12倍；②降雨后第1天田面水氮素浓度骤降，氨氮、硝氮分别减少86％、89％，降雨过程扰动河道底泥使大量氮素扩散到河水导致氮素浓度会有小幅度升高。因此在降雨过程应控制向稻区外界河流排水，否则易造成面源氮污染。

英文摘要：

Based on one modern agricultural integrated management demonstration district of Zhangjiagang Yonglian Modern Grain Production Base, two testing fields are selected to study the nitrogen changes laws in the paddy field surface water and river water in the south intensive paddy region through collecting the samples from the surface water and river water at the same time. The results indicate that： ①the closed irrigation river can accumulate nutrients so that its nitrogen concentration is much higher than that of the surface water and the NH＋^ --N concentration is even 12 times as that of the surface waters; ②The nitrogen concentration of paddy field surface water has a sudden drop in the first day after rain. The NH4＋ --N and NO~- --N will decrease by 86~, 89~, respec- tively. But the nitrogen concentration of river water has a little rise because that the river bottom mud is stirred by rain and the nitrogen is diffused to the river water. Therefore the drainage water to the outside river of the grain production district should be controlled in case of the Non-point source pollution.