Economic and environmental effects of nutrient budgeting strategies in animal excreta treatment: A case study from rural China

The purpose of this paper is to optimize manure allocation through nutrient budgeting strategy to meet crop nutrient requirements under maximizing economic returns and environmental constraints, and then to evaluate the economic and environmental effects of different nutrient budgeting strategies in animal excreta treatment.

In this study, a holistic integrated “ecological-economic” model is developed. It incorporates the systems of animal-crop production and waste treatment is developed for a pilot pig farm in China in order to simulate the economic and environmental effects of several nutrient budgeting strategies in excreta treatment for resource use.

The results reveal nutrient management deficiencies cause some serious environmental problems. The operations including biogas and composting are economically and environmentally efficient methods for manure management through nutrient budgeting strategy in an intensive animal farming with limited access to cropland. The nutrient budgeting strategy of constrained phosphorus, however, creates better environmental effects and brings more income from the waste treatment than the strategy of constrained nitrogen. The current standard of manure application in cropland which emphasizes on crop requirements for nitrogen should be reconsidered.

The paper is an original work and its methodology makes a meaningful contribution to understanding the relations between different nutrient budgeting strategies and their economic and environmental effects.