地表控制排水对氮质量浓度和排放量影响的试验研究

Experimental study on effect of controlled drainage from ground surface on concentration and discharge of nitrogen

为减少农田排水对水环境的面源污染,探讨了不同时段暴雨产生的地表径流中氮质量浓度和排放量的变化规律,对比研究了南方丘陵地区农田地表控制和非控制排水对氮质量浓度和排放量的影响.试验结果表明,非控制排水各时段平均氮排放质量浓度高于控制排水平均氮排放质量浓度,控制排水量比非控制排水量有所减少,地表控制排水可显著减少农田氮排放量.

For reduction of non-point pollution in water environment caused by drainage from croplands, a discussion was made to find out laws of concentration and discharge of nitrogen from surface runoff for different periods of time caused by heavy rains, and a comparative analysis was perfonned of effects of controlled drainage and non-controlled drainage from croplands on the concentration and discharge of nitrogen in south mountainous regions. The results show that the mean nitrogen discharge in each period of time under non-controlled drainage are higher than that under controlled drainage and that controlled drainage can effectively reduce the drain discharge. As a result, controlled drainage from ground surface can reduce nitrogen discharge from croplands remarkably.