The project aims to answer the following research questions:

• How do the following fertilizer variants (N, P, K, NP, NK, NPK, PK, manure and manure) affect plant species composition, feed yield, feed quality, root mass, rooting depth, carbon reserves and various phosphorus fractions in permanent grassland soil?
• What influence does a green fallow with and without removal of above-ground biomass have on plant species composition, root mass, rooting depth, carbon reserves and various phosphorus fractions in permanent grassland soil?
• What influence do mineral fertilizers, manure and fallow land have on the carbon sequestration potential of permanent grassland soils?
• Are soils beneath permanent grassland saturated with organic carbon?