中文摘要：

以沂蒙山区的棕壤为研究对象,采用模拟降雨的试验方法,基于复合肥和保水剂＋复合肥2种处理,分析保水剂对氮、磷流失的保持效应。结果表明：（1）保水剂具有削减径流和抑制产沙的作用,其中保水作用更为明显;（2）径流态氮、磷的流失量随保水剂保水作用明显减少,保水剂＋复合肥处理下NO-3-N、NH＋4-N、TN、PO4-P和TP的流失量较复合肥处理下分别减少24.14%,22.04%,30.23%,51.86%和16.47%;（3）保水剂对磷素的强吸附改变了其流失机制,但未改变氮素的流失迁移机制;（4）保水剂减少氮、磷淋失的效益达到25%以上,且这种保肥效应主要是通过控制淋溶液减少而实现。

英文摘要：

A simulated rainfall experiment was conducted to determine the controlling effects of water retaining agent on nitrogen and phosphorus losses under two treatments on brown soil in Yimeng mountainous area.Results showed that：（1）Water retaining agent not only decreased runoff but also sediment yield,but the effect on water retention was more obvious.（2）Losses of nitrogen and phosphorus greatly reduced with the water retaining agent.The loss amount of NO3-N,NH＋ 4-N,TN,PO4-P and TP from the treatment of water retaining agent and compound fertilizer decreased by 24.14%,22.04%,30.23%,51.86% and 16.47%respectively,compared with the compound fertilizer treatment.（3）Water retaining agent changed phosphorus loss mechanism through the strong absorption,while it unaltered nitrogen loss mechanism.（4）Nitrogen and phosphorus losses with leaching solution decreased by above 25% under the action of water retaining agent,and the obvious fertilizer conservation was mainly caused by the decrease of leaching volume.