This article evaluates fertility attributes, such as density, total volume of pores, and fractions of organic matter, including fulvic acid, humic acid, and soft organic matter, in a distrophic Oxisol, under perennial agriculture, pasture, and forest, in an Amazonian rural settlement called Machadinho d'Oeste, Rondônia. Fieldwork was done in 2004 when superficial soil horizons were sampled at depths between the soil surface and 0.1 m. Soil fertility increases under perennial agriculture, with lower acidity and higher amounts of nutrients. No significant difference was observed in soil organic carbon. However, variations in organic fractions were due to lower levels of soft organic matter and stronger relationships between soluble alkaline humic substances in comparison with soil humines under perennial agriculture. In areas of pasture, animal movement increased soil density and decreased the total volume of pores.
soil management; Amazon soils; soil properties
