Organic farming is the most widespread cropping system using alternatives to mineral fertilisation with continuously increasing significance in European agriculture. In organic farming systems, mineral nutrients are largely bound in complex organic compounds and exceptionally also in sparingly soluble mineral fertilisers such as rock phosphate. As compared with mineral fertilisation, this requires a more intense expression of mechanisms for nutrient mobilisation and nutrient acquisition, both, in plants and soil microorganisms.
WP05 investigates perspectives for the use of bio-effectors in organic farming and low-input systems for improvement of plant nutrient supply via an extended rooting with more root branching and root hairs and the stimulation of fungal symbionts (mycorrhiza). Moreover, various bio-effectors have the potential to mobilize sparingly available sources of mineral nutrients, such as phosphate and micronutrients and liberate bound forms of P, N and other essential elements from organic fertilisers. WP05 will unravel the capacity of candidate bio-effectors from WP01-04 to improve plant growth and nutrient uptake in greenhouse and small scale field experiments and addresses also the efficiency of bio-effectors in combination with organic amendments based on recycling products (WP06), green manure, and mineral recycling fertilizers (WP06) to promote plant growth and nutrient uptake in various soils of different European regions used for organic agriculture.