Recycling of nutrients in organic waste and bio-based fertilisers

There is an increasing realisation that recycling of nutrients and organic matter from agricultural and urban waste is important for sustainability of agricultural production systems. When waste is utilised on arable land, its fertiliser value and effects on soil quality should be optimised.

Our group has extensive experience with methods to assess nutrient turnover and availability from waste materials as well as their effect on soil quality. We also work with various methods and technologies to upgrade waste products, using different treatment technologies, such as composting, anaerobic digestion, gasification (biochar production) and microbial inoculants, in order to improve their quality and value as biofertilisers. Our research focuses on how these different waste treatment technologies affect the fertilizer value and soil fertility and quality, incl. potential negative effects of waste or treatment derived xenobiotics negative effects on ecosystem and human health.

Another research focus is the evaluation of leguminous green manures and catch crops, and their contribution to nutrient supply, turnover and balances, especially in low input in farming systems.

Techniques include isotopic methods, diffusive gradients in thin films and numerous extraction procedures. In addition, the group has experience with chemical characterization methods which can be used to determine the composition of the wastes as well as speciation of nutrients.