Agricultural non-point source pollution caused by excessive fertilization is a problem in the North China Plain. The experimental site was at a modern high-tech agricultural park in Dezhou City of Shandong Province that is located within the lower Yellow River impact plain. The fertilization, irrigation, and crop management in the modern agricultural park were investigated to determine the proportion of nitrogen and phosphorus loss of the total input. An ecological drainage ditch was constructed in the modern agricultural park in 2016. At the same time, a Doppler flowmeter and a runoff automatic acquisition instrument were installed in the inlet and outlet of the ecological drainage ditch for monitoring the flow of runoff and collecting runoff samples under natural rainfall in 2018 and 2019. The nitrogen, phosphorus, and sediment runoff contents were determined in the laboratory in order to calculate the loss of nitrogen and phosphorus from farmland runoff and the nitrogen and phosphorus interception rate of the ecological drainage ditch. The results showed that there were a total of 13 runoff events in 2018 and 2019 and that the average concentration of total nitrogen and phosphorus in farmland runoff was 2.63–18.84 mg·L⁻¹and 0.81–13.14 mg·L⁻¹ in both years combined, respectively. The main forms of nitrogen found in runoff were NO₃⁻-N, and the main form of phosphorus found in runoff was particulate phosphorus. The amount of nitrogen and phosphorus lost through runoff was 2.90% and 5.07%, respectively, of the average nitrogen and phosphorus input from both years combined. Runoff was generated when daily precipitation was above 17.4 mm and daily maximum precipitation intensity was above 5.1 mm·h⁻¹. There was a linear relationship between daily precipitation, daily maximum precipitation intensity, and the amount of runoff after natural rainfall. A linear regression equation was established to predict the amount of runoff in the study area. The results indicated that ecological ditches in the watersheds of modern agricultural parks could be used to intercept nitrogen and phosphorus from farmland runoff effectively.

过度施肥造成的农业面源污染是华北平原的一个问题。试验地点位于山东省德州市的一个现代高科技农业园区，位于黄河下游影响平原。通过对现代农业园区施肥、灌溉、作物管理等方面的调查，确定氮、磷损失占总投入的比重。2016年在现代农业园区建设了生态排水沟，同时在生态排水沟的进出水口安装了多普勒流量计和径流自动采集仪，用于监测径流流量，采集径流样本2018 年和 2019 年自然降雨。氮、磷、为了计算农田径流氮磷流失量和生态排水沟的氮磷截留率，在实验室测定了泥沙径流含量。结果表明，2018年和2019年共发生13次径流事件，农田径流全氮、全磷平均浓度为2.63～18.84 mg·L^-1和 0.81–13.14 mg·L ^-1两个年份的总和。径流中氮的主要形态是NO ₃ ^- -N，径流中磷的主要形态是颗粒磷。径流损失的氮、磷分别占两年平均氮磷输入量的 2.90% 和 5.07%。日降水量大于17.4 mm，日最大降水强度大于5.1 mm·h ^-1时产生径流. 日降水量、日最大降水强度与自然降雨后径流量呈线性关系。建立了线性回归方程来预测研究区的径流量。结果表明，现代农业园区流域生态沟渠可有效截留农田径流中的氮、磷。