Pollution of water and land is a common challenge in the SUDOE space. Deficiencies in the management of agricultural and livestock soils, and in particular the inadequate application of fertilisers in agricultural holdings, favour the pernicious concentration of nutrients in both surface and groundwaters, as well as soil deterioration. There is growing concern in the SUDOE space about the contamination of water and soil by phosphates from agricultural and livestock activity. Phos4Cycle seeks to promote the protection, conservation and recovery of soils and bodies of surface and groundwater affected by or at risk of phosphate contamination. To this end, the project proposes, on the one hand, to develop a common strategy and an action plan for the management of phosphates associated with agricultural and livestock activity in rural areas to improve agricultural practices, and to establish a pilot project to improve the monitoring of phosphate flows and the forecasting of the risk of eutrophication in river basins. It is expected that the project will support farmers and ranchers thanks to management that favors the sustainability of water and soil, as well as the authorities and agency with competence in the matter. The project benefits from transnational collaboration to combine efforts of entities that can carry out phosphate flow monitoring pilots with a high degree of technology in different contexts (in terms of watershed, climate, soil, agricultural activity and management system), and that have identified soil and water phosphate pollution as a priority. Phosphate pollution, unlike nitrate pollution, is a relatively little-known topic. Phos4Cycle is an opportunity to apply cutting-edge technology in remote control of water thanks to the analysis of physicochemical and biological parameters through surface images, as well as the environmental monitoring of micro contaminants and inorganic pollutants.