Carbono orgânico total e frações da matéria orgânica em diferentes distâncias da cepa de eucalipto

Abstract

The knowledge concerned to the horizontal and vertical distribution of organic carbon and organic matter fractions on remaining eucalyptus stumps in the field leads to a better comprehension about the changes that may occur in these features along the cultivation. This work aimed at determining the variation of total organic carbon in soil and organic matter fractions at different horizontal distances from remaining eucalyptus stump, at different ages, in the direction of the stump line. So, soil samples were collected around the eucalyptus’s stump from the previous rotation, with 31 and 54 months-aged, and at the distances of 30, 60, 90, 120 and 150 cm, at 0-10, 10-20 e 20-40 cm depth layers. The soil samples were analyzed about: total organic carbon (COT) and carbon concentration on humic substances (SH) and on the light free fraction (FLL). The results indicated variation on organic carbon concentration from several fractions of soil organic matter as long as it hold off from the remaining eucalyptus’s stump (CRE) with 31 and 54 months-aged. The C concentrations of the fulvic acids fraction, humic fraction, SH and COT get variable with CRE’s age. The major C concentrations of the several soil organic matter fractions on the surface layer reflect the deposition and maintenance of forest residues on the soil surface, mainly after forest harvesting.