The phosphorus cycle from land to sea in China

Phosphorus (P) is essential for crop growth but overuse of P fertilizer has caused significant soil P surpluses, low P use efficiency and serious water pollution in China. Until now, there has been no integrated quantitative study on P flows to land, uptake by crops, accumulation in soil, losses to surface water and export by rivers to sea in China. This study aims to explore the P flows from land to sea in China, assess the historical spatial-temporal changes, and investigate the future changes in response to changes in management. This will be done by adapting and applying the spatial explicit IMAGE-GNM and DPPS model to: (i) analyse the soil P dynamics in agro-ecosystem systems at global scale with a focus on China, (ii) explore the changing loads and sources of P in Chinese rivers and coastal seas, and (iii) assess the future water quality in China under different Shared Socioeconomic Pathways (SSPs), included in 5 chapters of the thesis