Increased Phosphorus Losses in the Food System in China and Region-Specific Mitigation Strategies to Ensure Losses Below Safe Limits

Sustainable phosphorus (P) resource management is crucial for food security and environmental sustainability. Overuse of P in intensive cropping systems has led to severe eutrophication problems. Here, we examined the trends and driving factors of (a) P losses from the food chain in 31 provinces in China over the period 1980-2016 and (b) predicted 2030 losses under different scenarios using the NUFER model and the Geographical Detector model. The P losses increased 5-fold between 1980 and 2016. Population density and livestock density are the main forces driving P losses. Large spatial variability exists in P losses across the country, with Central South and Southeast China regions as the hotspot areas. The scenario analysis showed that reduction of P pollution below safe levels can be achieved in most Chinese provinces through improved nutrient management adapted to site conditions. In low-risk regions, priority should be given to reducing mineral P fertilizer input and P losses in cropping system, while avoiding crop yield decline. In medium-risk regions, the focus should be on reconnecting livestock and crop production to enhance P recycling. In high-risk regions, comprehensive P management measures should be implemented across the entire food chain, including crop production, animal production, food processing, and human consumption systems. Specific actions include reducing livestock density, increasing fertilizer application taxes, improving food processing technologies, and adjusting dietary structures. The findings are critical to support policies for achieving region-specific sustainable P resource management across China.