Changes in phosphorus use and losses in the food chain of China during 1950–2010 and forecasts for 2030

Abstract

China has become the largest mineral phosphorus (P) fertilizer consumer in the world, but current use is not sustainable. Here, we report on a quantitative analysis of the P use and losses in the food production–consumption chain and of their relationships with socio-economic indicators for the years 1950–2010. Pathways to a more sustainable P use in 2030 were explored through scenario analyses, using the Nutrient flows in Food chains, Environment and Resource use model. Non-linear relationships were observed between changes in P use and changes in gross domestic production (GDP), suggesting a decoupling of P use from the main economic driver. More or less linear relationships were observed between changes in P use and changes in the percentages of vegetable and fruit and animal derived food in human diets. Total P losses increased from 0.2 Tg in 1950 to 3.1 Tg in 2010, while P use efficiency in the food chain decreased from 35 % in 1950 to 6 % in 2010. Our estimates suggest that 79 Tg P has accumulated in agricultural soils, 16 Tg P accumulated in landfill, and 48 Tg P has leached or has been discharged to water bodies during the past 60 years. Most of the accumulation and discharges took place in the last 10 years. We analyzed five options for increasing P use efficiency in the food chain by 2030, i.e., balanced P fertilization in crop production, precision animal P feeding, improved manure management, diet changes, and the integration of these four options. The integral adoption of these four options will increase P use efficiency in the food chain from 6 % in 2010 to 26 % in 2030. Total mineral P fertilizer use will decrease by 69 % and P losses by 68 % relative to the business as usual scenario. In conclusion, current P fertilizer use and losses are coupled to dietary choices, but have become decoupled from GDP. Further decoupling may occur when P use is defined by science-based P requirements for crops, animals and humans.