QUALITY OF SOIL SURFACE LAYER UNDER FOREST, PASTURE AND CROPPED AREAS

Abstract

This study aimed to quantify physical, chemical, and biological characteristics of soil and to evaluate the quality of a red-yellow Argissol under natural vegetation and cultivated for pastures and crops. Soil samples (0-10 cm depth) were collected in the following environments: forest (I); pasture of Brachiaria brizantha established through maize intercropping (II); pasture of B. brizantha with ten years of use (III); maize monocropping under no-tillage system (IV); and pasture of B. Brizantha, estabilished after soybean monocropping under no-tillage system (V). The following traits were measured: physical (soil density, total porosity, geometric average aggregate diameter, gravimetric moisture, texture, water retention capacity, and flocculation level); chemical (pH in water, available P and K, residual P, Ca, Mg and Al, H+Al, organic carbon, base sum and saturation, CTC, Zn, and Cu); microbiological (microbial biomass carbon, basal respiration, microbial and metabolic quotient, and acid and alkaline phosphatase enzymes activity, and ?-glucosidase). In comparison with the reference system (I), the soil quality rank for the environments was V, II, IV and III (lowest quality for the exclusive pasture). Therefore, in environments with crop-livestock integration, the edaphic environment quality was better than in monocrops. According to the management process used, it was possible to bring soil quality near to the reference environment.

KEY-WORDS: Crop-livestock integration; no-tillage; corn; soybean; sustainability.