【摘要】 【目的】氮、磷的流失已成为农业面源污染的最重要来源之一。探究和比较麦稻两熟农田以及杨树林地的降雨径流特征、径流水中氮磷流失情况,为预防地表水富营养化提供参考。【方法】在洪泽湖河湖交汇区典型农田和林地设置径流池,进行了为期1年的地表径流以及氮磷流失监测。【结果】麦田、稻田与杨树林地产生径流的最小降雨量分别为4.2、3.3、22. 8 mm,随着降雨量增大,杨树林地径流量增幅远小于农田。除了麦田总氮、硝态氮、总磷和可溶性磷流失量与降雨量相关性不明显外,其余各形态氮磷元素流失量基本随降雨量的增加而增加。麦田和杨树林地处在旱地状态下,其氮素流失分别以硝态氮为主,磷素流失以颗粒态磷为主;而稻田处在淹水条件下,氮、磷的流失分别以铵态氮和可溶性磷为主。杨树林地氮磷流失量都比农田小,全年总氮、可溶性氮、硝态氮和铵态氮总流失量分别只有农田总流失量的22. 61%、23. 79%、23. 46%、24. 59%,总磷、可溶性磷和正磷酸盐总流失量只有农田总流失量的0. 81%、0. 77%、0. 67%。【结论】与农田相比,林地能够更好地控制径流养分流失,可以在面源污染控制中发挥重要作用。更多还原

【Abstract】 【Objective】The loss of nitrogen and phosphorus has become one of the most important sources of agricultural non-point source pollution. The purpose of this study was to explore and compare the characteristics of rainfall runoff and the regularities of nitrogen and phosphorus loss in runoff water of a wheat-rice double cropping field and poplar forest land.【Method】In this study,the surface runoff and nitrogen and phosphorus loss were monitored in the intersection area of Hung-tse Lake and Huaihe River for one year by collecting runoff.【Result】The minimum rainfall that produced runoff from the wheat field,rice field,and poplar forest land was 4.2,3.3 and 22.8 mm,respectively. With the increase of rainfall,the increase of the poplar forest runoff was much lower than that of the farmland. The total nitrogen,nitrate nitrogen,total phosphorus,and soluble phosphorus loss were not significantly correlated with rainfall,but the loss of different states of nitrogen and phosphorus increased with the increase in rainfall. The wheat field and poplar forest land were usually in the dry condition,where nitrogen loss was mainly caused by nitrate nitrogen and phosphorus loss was primarily caused by particulate phosphorus. The rice field was in a flooded condition,and the loss of nitrogen and phosphorus was caused by ammonia nitrogen and soluble phosphorus,respectively. The nitrogen and phosphorus loss in the poplar forest was lower than that of the farmland,and the total loss in a year of total nitrogen,soluble nitrogen,nitrate nitrogen,and ammonia nitrogen in the polar forest land was 22.61%,23.79%,23.46% and 24.59% that of the farmland,respectively. Total phosphorus,soluble phosphorus,and orthophosphate in the polar forest land was 0.81%,0.77% and0.67% that of the loss in farmland,respectively.【Conclusion】Therefore,forest land can better control the loss of runoff nutrients compared with farmland,and plays an important role in the control of non-point source pollution.更多还原