LAUSR

Nutrient budget is one of the Organization for Economic Co-operation and Development (OECD) agri-environmental indicators. A model was developed for regional nutrient management in Korea. In this study, a sensitivity analysis of parameters of a nutrient budget model was performed for two regions with intensive livestock farming in Korea. In the nitrogen budget, gross nitrogen surplus (GNS) and hydrospheric nitrogen surplus (hNS) were analyzed separately. For GNS, the most influential parameters were excreta production per swine in Hongseong and excreta production per beef cattle in Anseong. For hNS, N content of solid manure in swine and beef cattle were the most influential. For GNS and phosphorus surplus (PS), excreta production per livestock and the N(P) in the excreta of livestock were the predominant parameters. Livestock excreta showed a high sensitivity in both areas because the livestock headcount was high; thus, the excreta accounted for a large share of the input parameters for the model. Therefore, calculating reliable regional nutrient budgets would require further research on excreta production per livestock and the N(P) excretion in livestock. The nutrient budget model could be implemented for agri-environmental policy e.g., environment friendly regional livestock farming and sustainable integrated crop livestock systems.