Avaliação dos atributos do solo sob diferentes usos na região de Humaitá, Amazonas

Abstract

The implementation of forestry, agricultural and livestock activities is modifying the original vegetation of much of the Brazilian territory. Natural ecosystems such as savanna and the Amazon rain forest have been losing their original features, making room for these activities. The objective of the present study was to evaluate the soil attributes of areas under different land uses in the region of Humaitá. The study was conducted between 2012 and 2013 in the municipality of Santa Rita Humaita, Amazonas state, Brazil. The soil was classified as Alitic Plinthic Haplic Cambisol. Three areas were selected: area of abandoned pasture, area of abandoned agriculture, and natural area with native vegetation. In each use system, an area of 60 × 80 m with twelve sampling points was demarcated and soils were collected in layers from 0.00 to 0.05 and 0.05 to 0.10 m depths with preserved structure, totaling 24 samples per use system. The following physical analyses were conducted: texture, macroporosity, microporosity, total porosity, soil water content, bulk density and aggregate stability. The following chemical analyses were carried out: pH, potential acidity, exchangeable aluminum, organic carbon and carbon stock. Univariate and multivariate statistical analyses were performed. The replacement of the native vegetation with use systems causes changes in physical and chemical soil properties. The use of multivariate techniques was effective in distinguishing environments of the use systems studied.