为了究明水稻、水生植物及土壤因子等对水的净化力,作者研究了不同流速条件和不同处理区田面水中溶存的无机态氮和磷的浓度及数量的变化情况。试验区分成水稻栽培区(1980年和1981年7-9月为栽培水稻期)和裸地区等处理,田面水流速度分40米/小时和100米/小时,每区宽18米,长150米,在进水口和12.5、25、50、100及150米处取水样测定pH、溶存氧气(DO)及NH_4-N、NO_2-N、NO_3-N、PO_4-P等。 In order to elucidate the water purification capacity of rice, aquatic plants and soil factors, the authors studied the changes of concentrations and quantities of dissolved inorganic nitrogen and phosphorus in surface water of different flow rates and treatments. The test area is divided into rice cultivation areas (cultivated rice period from July to September 1980 and 1981) and bare areas. The surface water flow rate is 40 m / h and 100 m / h, each area is 18 m wide and 150 m , PH, dissolved oxygen (DO) and NH_4-N, NO_2-N, NO_3-N, PO_4-P, etc. were measured at the inlet and 12.5, 25, 50, 100 and 150 meters respectively.