Physical, chemical and biological attributes of a cerrado Oxisol under different forest species

The objective of this study was to evaluate the impact of forest plantations on the physical, chemical and microbiological attributes of a cerrado Oxisol. Soil samples were collected at 0-10 cm depth from sites cultivated with pinus (Pinus tecunumanii), eucalyptus ( Eucalyptus grandis) and carvoeiro (Sclerolobium paniculatum) for over 20 years. An adjacent native cerrado area was used as a reference of the original soil conditions. It was observed in relation to the native cerrado: increases in soil density under pinus and eucalyptus, reduction in the macroporosity under pinus, lower organic matter contents under pinus and eucalyptus, besides decreases in the soil pH and in the base saturation under pinus and carvoeiro along with an increase in aluminum saturation. Soil microbial biomass carbon under the pinus, eucalyptus and carvoeiro sites was about half of that found under cerrado. The activities of acid phosphatase and arylsulfatase were inhibited by pinus and stimulated by carvoeiro. Among the forest systems evaluated, pinus promoted the greatest reduction on soil quality. The microbiological variables were the most sensitive to detect the effects of these systems on soil quality.