After more than 20 years from its departure point in Beijing 2000, the Symposium lands for the second time in South America, where it will tackle the issues of the current P cycle, in the agroecosystems of the region but also of the world. On one hand, many agroecosystems in the world, such as South American one, face phosphorus scarcity for sustaining economically viable levels of primary and secondary production. On the other hand the systematic addition of P for attaining those levels of productivity has put under consideration how to manage high phosphorus which gives rise to problems of eutrophication mostly in aquatic ecosystems. That dichotomy of the phosphorus cycle in these agroecosystems pushes both the scientific society and the agricultural sector to join to look for sustainable solutions. Therefore, it is fundamental to congregate actors from different sectors in the PSP7 such as the academia, educative sector, private sector, government and other stakeholders, from the region and the world. The scope of the topics will range from fundamental insights of phosphorus biogeochemical cycles to applications such as crop breeding, fertilizer development, soil management and performance of environmental impact assessments. The conference also aims to attract many scientists from developing countries where phosphorus scarcity is a major issue. -- The themes of PSP7 are:1.- Phosphorus forms, availability and cycling in soils. -- 2.- Phosphorus acquisition by plants and microorganisms. -- 3.- Phosphorus utilization and signaling in plants. -- 4.- Sustainable intensification of phosphorus supply in food production. -- 5.- Impact of phosphorus on environmental quality and on biodiversity. --