Estimation of Carrying Capacity of Livestock Farm Based on Maximum Phosphorus Load of Farmland and GIS Spatial Analysis Technology

To avoid the environmental pollution caused by livestock manure and provide rational layout of livestock farm, we estimated the livestock manure phosphorus load by the excretion coefficient method and have developed a livestock manure nutrient distribution model. The livestock manure phosphorus was distributed to farmlands using this model and spatial analysis technology. The carrying capacity of livestock farms was calculated based on the maximum livestock manure phosphorus carrying capacity of farmlands and expressed in pig for the Shangjie town, China. The results showed that the maximum, minimum, average and total livestock manure phosphorus carrying capacity of farmlands was about 55.97, 0.74, 12.21 and 13,382.90 kg respectively, and the total load of 2854.79 kg manure phosphorus from livestock farms surpassed the carrying capacity of farmlands in Shangjie town in 2011. The results also demonstrated that the maximum, minimum, average and the total carrying capacity of livestock farms was respectively, 792, 10, 157 and 9128 pigs. Most of the livestock farms in the town had carrying capacity of less than 300 pigs and only six farms had carrying capacity of livestock more than 500 pigs. The results could provide decision support for the spatial layout of livestock farms, controlling environmental pollution caused by livestock manure.