Nitrogen stabilization in fertilization practice: optimization by regionalization based on meteorological and edaphic parameters

Within the R&D project StaPrax-Regio, highly efficient N-stabilized fertilization strategies are identified based on site-specific agrometeorological and soil characteristics. Derived strategies will be transferred to fertilization practice using innovative advisory tools. The aim of the project is a significantly improved utilization of the diverse and complex beneficial effects of N-stabilized fertilization (e.g. reduction of N losses, improved N availability in soil, promotion of root growth, improvement of seedling development) to optimize fertilizer N efficiency. Currently, this has been insufficiently achieved for winter cereals. However, the previous project StaPlaRes demonstrated that a significant increase in N use efficiency can be achieved by an optimized adaptation of N-stabilized fertilization strategies to site-specific soil and weather conditions.

The Deutscher Wetterdienst prepares agro-meteorological analyses for 85 test fields with different winter grain types in Germany: based on long-term measurements such as air temperature and precipitation as well as based on modeling with the agro-meteorological models AMBAV (AgrarMeteorologische Berechnung der aktuellen Verdunstung) and BEKLIMA (BEstandsKLIMA) for e.g. soil moisture and soil temperature. Thus, more differentiated statements about the dependencies of plant development on agro-meteorological conditions are achieved. In addition to the model evaluation with measurements ​during the project, the model data and the site analyses are used to generate regionalized statements on e.g. temperatures, precipitation and phenological development during the main fertilization period. In combination with parallel soil and plant cultivation analyses, highly efficient site-specific fertilization strategies will be identified. For this purpose, existing consulting tools (e.g. BESyD) and GIS-based maps will be used and developed further. In order to take seasonal influences into account, an agro-meteorological model is currently developed in the AMBER environment, which should serve as an additional agro-meteorological decision-making aid at an early stage (if possible a few weeks) before each upcoming fertilization application.