Global phosphorus cycling: The impact of international commercial trading and the path towards sustainable phosphorus management

Abstract

Phosphorus is vital for global food production, but its use in commercial fertilizers has led to significant changes in the global P cycle. This has resulted in the depletion of phosphate rock deposits and increased eutrophication in lakes and oceans. While attempts have been made to quantify phosphorus flow at a country or regional level, there is still a lack of comprehensive understanding of how international commercial trading affects global phosphorus cycling over time. Through substance flow analysis, this research has found that the total global P flows through the five major P trade products have increased by around 5.4 Tg P between 2000 and 2019, with agricultural products trade having the fastest growth rate. The net P budget in the global trade of products changed among countries throughout these twenty years and relates to local natural resources and policies. Overall the global P flow has shifted from phosphate rock dominated structure to phosphate fertilizers and phosphoric acid dominated structure from 2000 to 2019, with centralized production reducing P resource losses during manufacturing. However, there are risks associated with P redistribution, including P resource shortages in certain countries/regions (e.g. Japan) and P pollutant accumulations in others (e.g. Brazil). These results highlight the importance of trade on the global phosphorus cycle and the need for both consuming and supplying countries/regions to work together to propose effective solutions for sustainable management of P in the future.