Physical and biological attributes of Yellow-Red Argissol of Amazon under different systems of use and management

Abstract

The soil quality is defined by the interaction among chemical, physical and biological attributes, which are fundamental as indicators of sustainability of the agriculture systems. Thus, the study aimed to verify the effect of the management and use systems on physical and biological properties of a Yellow-Red Argissol in the Amazon region. The study was conducted in Alta Floresta, state of Mato Grosso (Brazil) (09 º 56'20 "S and 55 º 55'42" W; altitude of 285 meters). A block design was adopted, with 6 types of soil occupation and with 5 replications in plots of 100 m² each. The systems used were: natural vegetation, conilon coffee (Coffea canephora), conventional tillage (field to grow soy and maize crops), Panicum maximum (Mombaça) pasture, Brachiaria brizantha (Brizantão ou braquiarão) with liming and Brachiaria brizantha without liming. The physical attributes evaluated in this study were: macroporosity (Ma), microporosity (Mi), total porosity (Pt) and density of soil (Ds). The biological attributes were: basal respiration; microbial biomass carbon (MBC), microbial quotient and metabolic quotient (qCO₂). The native vegetation system had lower microporosity and the higher rates of MBC. The qCO₂ was greater in Panicum maximum pasture. Systems with pastures promoted the reduction of macroporosity and total porosity of the soil. The conventional farming systems showed lower biological quality when compared to the other systems.