西湖名胜区茶园地表径流水的氮磷流失研究

在西湖风景名胜区代表性茶园地设置径流小区,研究常规施肥条件下茶园生态系统地表径流及其氮磷流失状况。结果表明,1年的观察期内(2010年7月-2011年6月),自然降雨条件下常规施肥茶园地表径流总氮平均浓度为5.5 mg.L-1,总磷平均浓度为0.5 mg.L-1,地表径流流入水体存在水体富营养化的风险。可溶性氮是茶园土壤氮素流失的主要形态;氮磷流失量、径流量与降雨量均呈极显著的正相关关系,各种氮素形态之间也呈极显著的相关性。研究结果表明,要避免下雨前施肥、少施肥料和挖沟施肥来减少氮磷的流失。

Preliminary study on surface runoff nitrogen and phosphorus loss in the West Lake tea plantation ecosystem

The effect of the conventional fertilization on runoff and nutrient losses in field conditions was investigated through setting runoff plots in tea plantation ecosystem in West Lake.The results showed that total nitrogen(TN)and total phosphorus(TP) concentration were 5.47 mg·L-1and 0.48 mg·L-1,respectively,in the period from July 2010 to June 2011,which indicated that surface runoff into the water would result in water entrophication.The results also suggested that soluble nitrogen was the main form of runoff nitrogen loss in the tea plantation system.The runoff and total nitrogen phosphorus losses were highly correlated with the precipitation during the period,suggesting that it can reduce nitrogen and phosphorus loss in the surface soil in the condition of less fertilizer,avoiding fertilization before raining,and trenching fertilization.