Main research question/goal
The goal of this project is to gain broad knowledge about the phosphorus cycle in agricultural soils through a literature review. Similar to nitrogen, phosphorus can stimulate eutrophication by reaching the groundwater and surface water after the application of fertilizer or manure on the agricultural soils. Phosphorus is possibly the limiting nutrient for eutrophication, and as such is gaining importance in the most recent versions of the Flemish ‘mestactieplan’ (manure legislation). Application standards for phosphorus on agricultural soils are becoming more strict. In contrast to nitrogen, processes concerning phosphorus in agricultural soils (availability to plants, reductions of yield and evolution of the soil phosphorus status at reduced fertilization, risks for and way of transport from agricultural soils to water,…) are less well known. This knowledge is, however, a crucial basis for (future) legislation.Research approach
During this two-year project, we review all published knowledge of the phosphorus cycle in agricultural soils. This literature study focuses on phosphorus availability, influencing factors as soil characteristics and fertilization strategies, working coefficients of manures, systems for fertilizer recommendations, consequences of reduced fertilization for crop yield, crop quality and soil status, risks for phosphorus losses, and phosphorus transport from soils to ground and surface water. Alternative measures for reduction of phosphorus concentrations in Flemish ground and surface water are examined along with the legislation and monitoring in similar European regions.Relevance/Valorisation
Understanding all the mechanisms of the phosphorus cycle in agricultural soils makes it possible to estimate the risks of reduced phosphorus application both for agriculture (reduced yield and soil P status) and for the environment (phosphorus losses towards ground and surface water). This enables targeting of a fertilization level which limits the risk for both the farmer and the environment. This knowledge of optimal phosphorus fertilization can be transferred to farmers. Moreover, the research results can contribute to a legislation which targets the phosphorus related problems in the most efficient way.