南方库区生态农业小流域面源污染特征OA北大核心CSTPCD

In order to investigate the characteristics of nitrogen and phosphorus emission in a small ecological agriculture watershed,the small eco-agricultural Fendong watershed of Changhu Reservoir in Dazhan town,Yingde City,Guangdong province,was chosen as the research region,the content and diffuse pollution characteristics of nitrogen and phosphorus,the identification of the critical source area,and the effects of eco-agriculture on reduction of nitrogen and phosphorus emission were studied by means of field observations and laboratory measurements.The results showed that the water pollution was low at the watershed scale,most of the water quality were not worse than level Ⅲ.Total nitrogen(TN)and total phosphorus(TP)were the main pollution loads in the watershed,and the dissolved nitrogen was the main nitrogen composition(＞50％).The critical source areas included soil erosion,goose farms,residential areas,and pig farms.The total loads of TN and TP were 345.22 and 69.47 kg during the study period,respectively.The pollution load intensity into the river was low,and the inflow coefficients of TN and TP were 0.16 and 0.63,respectively.Above results indicated the effect of nitrogen and phosphorus emission reduction in the small ecological agriculture watershed was remarkable,and the absorption capacity of nitrogen and phosphorus was strong,which made the nitrogen and phosphorus pollution load low and the water quality good,so ecological agriculture should be worth popularized and widely applied.