Caracterização ambiental e predição dos teores de matéria orgânica do solo na Sub-Bacia do Salto, Extrema, MG

Abstract

Rational management in a watershed requires knowledge of several important parameters regarding the hydrology, including morphometric, vegetation cover and soil organic matter (MOS) amounts. The objectives of this study were to evaluate the morphometric characteristics, identify the existence of vegetation using the normalized difference vegetation index (NDVI) and analyze the spatial variability of the organic matter amount, obtained through combination of landscape properties of the Salto Sub-basin, Extrema, MG, Brazil. Digitalized topographic maps, satellites images and the Inverse Distance Weighted interpolation methods were used to acquire the MOS spatial variability. The Salto Sub-basin has a median tendency for flooding; drainage is efficient and highly branched. Most part of the Sub-basin is occupied by degraded pastures with vegetation with high biomass occurs mainly in headwater areas. The properties set that better estimated the MOS was slope, profile curvature, NDVI and topographic wetness index (TWI). In most of the study area, MOS showed medium amount (2.01 to 4.00 dag kg -1 ), with higher levels in areas of high altitudes (about 1,600 m) at the headwaters of the Sub-basin.