The anthropic interference have changed the original soil condition in Campos de Cima da Serra region, Brazil. This study aimed to evaluate the distribution of humic substances in an Oxisol under native pasture (CN), native burned pasture (CNq), native forest (MN), pine afforestation (FP) and annual crops (LA). The levels of total organic carbon (TOC) and C compartments of chemical soil organic matter (SOM) were determined. The use and management adopted affected the levels of TOC and C in the chemical compartments of the SOM. In comparison to CN, the MN increased the amounts of TOC, which remained unchanged in the CNq and was reduced by land uses with LA and FP. Changes in land use and management tended to reduce the C in humic fractions and modified the humic and fulvic acids distribution.
organic matter; vegetation burning; pinus
