A multi-plot mn-off experiment was carried out in a paddy field cultivated with wild rice stem ( Zizania caduciflora) and rice in rotation and with wild rice stem alone under conventional fertilization in Dianshanhu Region to study N and P losses and their non-point source pollution load. Results show that discharge of the non-point source pollutants, nitrogen and phosphorus, occurred mainly in the period from June to September. The mean mass concentration of TN in drainage could reach as high as 130.0 mg · L-1, mainly in the form of NH4+-N, which came mainly from inorganic fertilizer. During the wild rice stem growing season, the mean mass concentration of TP in drainage was in the range of 0. 104 -0. 777 mg · L-1 , mainly in the form of particle, which accounted for 73.5％ ～ 90. 3％ of TP ( except for August). Furthermore, TN non-point source pollution load of the rotation system and the mono-cropping system was 134. 8 and 88.6 kg · hm-2 . a-1 , respectively. Both were higher than those from other cropping systems in the Taihu Region,while TP non-point source pollution load was 1.52 and I. 06 kg · hm-2 · a-1 , respectively, lower than the average level of the common cropping systems in the Taihu Region. So it is important to set control of the use of nitrogen fertilizer and the nitrogen loss as priority for control of agricultural non-point sources pollution in the Dianshanhu Region.%在常规施肥条件下,通过大田小区径流试验研究了淀山湖区域特有的茭白-水稻轮作和茭白单作种植模式的氮、磷流失规律及污染负荷特征.结果表明,研究区氮、磷面源污染物排放主要集中在6-9月,排水TN平均质量浓度最高可达130.0 mg·L-1,以NH+4-N流失为主,主要来源于化肥施用;茭白生长期内,排水TP平均质量浓度为0.104～0.777 mg·L-1,以颗粒态磷为主,约占TP总量的73.5%～90.3%(除8月外).茭白-水稻轮作和茭白单作模式TN污染负荷分别为134.8和88.6 kg·hm-2·a-1,均高于太湖流域其他几种种植模式;而TP污染负荷则分别为1.52和1.06 kg·hm-2·a-1,低于太湖流域常见种植模式的平均水平.氮肥施用及氮素流失控制应作为淀山湖区域农业面源污染控制的重点.
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