The balanced fertilization of agricultural crops is important to produce high-quality agricultural products and to avoid over-fertilization. The main research target of our institute is to close nutrient cycles in agriculture (primarily those of nitrogen and phosphorus) and to optimize water availability. This is mandatory to minimize nutrient discharges into aquatic and terrestrial ecosystems and to protect the environment.

Secondary resources - how can recycled fertilizers be used?

The nutrient phosphorus (P) has become one focus of research due to the limited deposits of raw phosphate. An effective P recycling is of great importance to ensure agricultural production in the future.

Sewage sludge treatment and production of recycled fertilizers from precipitates and ashes represent a cornerstone for closing nutrient cycles and are particularly important with respect to P.

Technically, we face the challenge of reliable and safe evaluation of these recycled products and other organic and mineral fertilizers. While we are analyzing their agronomic efficiency, we also have to keep in mind their contamination with heavy metals and organic pollutants for appropriate evaluation.

Our institute is working on methods to standardize these procedures.

Promising recycling products are tested in field trials to determine their longer-term fertilization properties.

Nitrogen: Balancing in- and output

Our institute is working to improve nutrient efficiency in nitrogen (N) in order to minimize negative environmental impacts. In particular, we have to reduce nitrate pollution of ground and surface waters. Therefore, we develop and evaluate measures that aim to reduce leaching, e.g. in fertilizer application.

The institute is also responsible for calculating the national nitrogen balance and develops suitable methods for monitoring nitrate loads in agriculture for this purpose.

In research projects, we quantify the influence of fertilization and cultivation on the release of gaseous nitrogen compounds, especially ammonia and nitrous oxide, in order to derive mitigation strategies.

The optimum nutrition for healthy plants - macro- and micronutrients.

The influence of plant nutrition on yield and quality parameters and plant resistance to biotic and abiotic stress is also subject of our research. Here, the nutrient sulfur (S) is of particular importance because after desulfurization of industrial fumes in the late 1980s, S moved from being a pollutant to being a minimum factor in agriculture. Our institute investigates the influence of S on yield and quality of agricultural products but also on plant health and natural stress resistance.