分析了红池坝３个地点红三叶和鸭茅混播草地牧草产量与施氮、磷肥量的关系，提出施肥效应函数后，运用每一地点的土壤自然肥力状况与该效应函数建立土壤肥力与施肥量相关的草地施肥模型方程，然后通过该方程再与肥料和牧草价格建立关系函数，由此求出在不同土壤肥力条件下经济合理的施肥量，从而建立该地区草地的施肥优化模式。在不同地区不同土壤肥力条件下，牧草对施肥的反应情况是不一致的，而且牧草对氮、磷肥的吸收与彼此的施肥量及有效性有关。同时一般磷肥对混播草地中红三叶的增产作用较为明显，而施氮肥对混播鸭茅的促进影响较大。最佳施氮肥量为０．０３～０．１６ｔ／ｈｍ２，最佳施磷量为０．１６～０．４９ｔ／ｈｍ２。对于禾本科和豆科牧草混播草地，以少施或不施氮肥经济效益较好 The relationship between the yield of forage grass and nitrogenous and phosphorus fertilizers in the mixed grassland of Hongtangye and Dactylisophila bungei in three sites of Hongchiba was analyzed. After the fertilization effect function was proposed, the natural fertility of each site and the effect function were used to establish the relationship between soil fertility and Fertilization amount, and then establish the relationship function between fertilizers and forage price through this equation to find out the economic and reasonable fertilization amount under different soil fertility conditions, so as to establish the optimal fertilization mode of grassland in this area. Under different soil fertility conditions in different regions, the response of forage to fertilization was inconsistent, and the uptake of nitrogen and phosphate by forage was related to the fertilization amount and effectiveness of each other. At the same time, the general effect of phosphate fertilizer on the yield increase of red clover in mixed sowing was obvious, while the effect of nitrogen fertilizer on the promotion of mixed sowing was significant. The optimum amount of nitrogen fertilizer was 0.03 ~ 0.16t / hm2, and the optimum phosphorus application rate was 0.16 ~ 0.49t / hm2. For the gramineous and legume pasture mixed grassland, less or no nitrogen fertilizer economic benefits