密云水库库区不同植物篱模式下的氮磷阻控效应

鉴于密云水库周边耕地氮磷等养分流失严重、作物产量远低于预期的问题，结合径流小区试验和统计学手段，观察并讨论了植物种植篱对氮磷流失效应的影响，进而提出更科学合理的农林复合模式。设置了4个不同物种的植物篱径流小区和一个裸地对照径流小区，监测它们在2020年度天然降水条件下的地表径流、泥沙以及养分情况。结果表明：1）4种植物篱种植模式都能够起到截流减沙，减轻水环境富营养化的作用，从而避免对下游水体的污染。其中桑树+野牛草植物篱效果最为显著，大雨雨强下可以减流57.96%，减沙96.64%，暴雨雨强下可以减流64.63%，减沙97.17%；对磷的相对拦截率约为80.72%，相对拦截量为 5.34 mg；对氮的相对拦截量26mg，相对拦截率约为88.27％，能有效减少地表径流中的氮、磷含量。 2）在考虑经济效益、社会效益和生态效益下，开展植物篱防控面源污染工作中，最佳的物种选择为桑树+野牛草，其次为黄芩+野牛草。野牛草在保持水土流失，防控面源污染方面效果十分显著，可以作为水土保持的先锋植物予以推广。

Nitrogen and Phosphorus Interception and the Control Effected by Different Hedgerow Patterns in the Miyun Reservoir Area

In view of the serious loss of nutrients such as nitrogen and phosphorus in cultivated land around Miyun Reservoir and the crop yield is far lower than expected, combined with runoff plot test and statistical means, the influence of plant hedgerow on nitrogen and phosphorus loss effect is observed and discussed, and then a more scientific and reasonable agroforestry composite model is put forward. Four hedgerow runoff plots of different species and four bare land runoff plots were set up to monitor their surface runoff, sediment and nutrients under natural precipitation conditions in 2020. The results show that: 1) the four hedgerow planting modes can cut off flow and reduce sediment, reduce water environment eutrophication, and avoid pollution to the downstream water body. The effect of mulberry + bison hedgerow is the most significant. Under heavy rain, it can reduce 57.96% flow and 96.64% sand, 64.63% flow and 97.17% sand; The relative interception rate of phosphorus is about 80.72%, and the relative interception amount is 5.34 mg; The relative interception amount of nitrogen is 26Mg, and the relative interception rate is about 88.27%, which can effectively reduce the content of nitrogen and phosphorus in surface runoff. 2) Considering the economic, social and ecological benefits, the best species selection for hedgerow prevention and control of non-point source pollution is mulberry + bison grass, followed by Scutellaria + bison grass. Bison grass is very effective in soil and water conservation and prevention and control of non-point source pollution. It can be popularized as a pioneer plant in soil and water conservation.