Since the mid-1980s, the National Soil Monitoring Network NABO has assessed the organic matter content in the topsoil. These data sequences should be expanded by determining carbon stocks in a larger part of the soil profile. Thus, until recently, NABO sampling includes also the assessment of organic matter in deeper soil layers.
Soils store roughly five times as much carbon as the surface biomass and represent the second largest greenhouse gas storage on Earth (the oceans being the largest). Moreover, organic matter significantly influences the storage and buffer capacities of soils, thereby regulating important soil functions in nutrient cycles and water balance. Organic matter is thus a key factor that plays a central role in securing sustainable and long-term soil use, specifically with regard to the consequences of climate change.