Soil fertility and plant symbioses are central to plant nutrition in organic farming. A fertile soil is in good physical, chemical and biological condition and can fulfil its ecological functions. Symbiotic root fungi (mycorrhiza) particularly promote phosphorus uptake by plants, while nodule bacteria, which live in symbiosis with legumes, make an important contribution to the nitrogen balance. In mixed organic farms, the nutrient cycle between plants and animals is closed as far as possible. However, with every product sold, nutrients are removed, which can cause the soil to become impoverished in the long term. In order to close the nutrient cycle between society (waste, sewage sludge) and agriculture, technologies are required that meet strict hygiene requirements as well as the nutrient and pollutant content of the recycled fertilisers. Additionally, they need to comply with the requirements of organic farming.
We are currently investigating several aspects of nutrient management, including: