Land use type affects soil organic carbon levels. Different land uses like grassland, cropland, and fallow land have varying amounts of soil organic carbon. Artificial grassland has the highest levels, while free grazing grassland has the lowest. Microbial biomass carbon and other fractions of soil organic carbon follow a similar pattern. These levels decrease with soil depth. The ratio of microbial biomass carbon to total soil organic carbon can indicate changes in soil fertility. This shows that different fractions of soil organic carbon respond differently to environmental changes.