Abstract: Based on 20 parameters obtained from field experiment,animal feeding experimerit and 4 years operation of eco-agricultural business,this paper discusses the source, pool and flux of nitrogen and phosphorus cycling in a combined agroanimal husbandry ecosystem. In order to fit the needs of animal husbandry development in the front Taihang Mountain Plain of North China,introducing legume into high-yielding area to build the entity of eco-agriculture business,is a sound strategy for nutrient cycling. It makes the utilization efficiency of mineral Nto be 66.6% and P 63.3% in the farmland ecosystem, and the recovery of Nis 86.6% and P 45.3% in the combined agroanimal husbandry ecosystem.

Key words: litter, simulated nitrogen deposition, microbial biomass C, microbial biomass N, microbial activity.