Effects of Controlled Drainage on TN and TP Concentration in Surface Runoff

摘要

This study was conducted to determine a surface runoff controlled drainage which reduced nitrogen and phosphorus losses from arable land.A field experimental project in flat topography was set up in southern China Jiangsu Province to monitor the concentration of nitrogen and phosphorus in the surface runoff.When cropland is covered with surface water caused by heavy rain,controlled drainage made it possible to reduce concentration of nitrogen and phosphorus by making surface water stay in the cropland for period of time.The surface runoff controlled drainage reduced drain flow by 12.7% compared with non-controlled drainage.The concentration of total nitrogen(TN) in non-controlled drainage is 10.55mg/L,only 5.1mg/L in controlled drainage.The concentration of total phosphor(TP) in non-controlled drainage is 8.48mg/L,only 4.4mg/L in controlled drainage.The loss of TN in non-controlled drainage is 516.7mg/m2,only 222mg/m2 in controlled drainage.The loss of TP in non-controlled drainage is 413.8mg/m2,only 191.6mg/m2 in controlled drainage.