Humusmanagement in österreichischen Dauergrünlandböden

In Austria, soils of permanent grassland are important for storage of organic carbon (C) due to their high soil organic matter stocks and large area. In permanent grassland, approximately 90 % of the total C stock are stored in the soil. Organic C stock in the soil layer 0–30 cm is on average 93 t C ha⁻¹. A considerable quantity of soil organic C (> 40 %) is stored in the subsoil (10–50 cm). Subsoils have a high potential for long-term soil C sequestration. Soil organic C stock is controlled by climate, soil properties (particularly soil moisture status, soil thickness), vegetation type (root biomass) and grassland management intensity. Plant roots and C-rich organic fertiliser are of utmost importance for soil organic matter build-up, which is generelly a slow process. In permanent grassland, soil organic C storage is highest at an intermediate management intensity (stocking rate: 1.2–1.5 LU per ha, 2–4 cuttings per year, annual application of cattle manure or composted cattle manure). Management practices designed to increase the annual soil organic matter turnover are more important than those designed to enhance the soil organic matter stocks. Soil C sequestration can trigger a trade-off between climate change mitigation and nature protection.