MICROBIOLOGICAL AND CHEMICAL SOIL PROPERTIES IN DESERTING AREAS IN THE SEMIARID REGION OF PERNAMBUCO STATE, BRAZIL

To analyze the process of degradation caused by natural or anthropogenic influences tools are required, preferentially low-cost, to indicate the degradation stages aiming the selection of techniques to reclaim degraded areas. The purpose of this study was to analyze the variability of microbiological and chemical soil properties as indicators of desertification processes in areas with increasing levels of degradation in the semiarid region of the State of Pernambuco, Brazil. Three environments were sampled: conserved, moderately degraded and heavily degraded in Floresta, PE. Seven samples were collected from four areas per environment (28 points per environment). Soil samples were collected from the 0-10 layer in dry and rainy seasons. Soil samples were used for chemical (pH, exchangeable bases, potential acidity, soil organic carbon, carbon stock, available phosphorus and cation exchange capacity), microbiological (microbial biomass carbon, basal respiration, microbial and metabolic quotients) and physical analyses (texture and bulk density). The data were analyzed using main components and t test. An effect of seasonality was observed for the soil properties, especially in the degraded environment. Principal component analysis identified microbial biomass carbon, potential acidity and percent of base saturation as most sensitive to the degradation level in the rainy and dry seasons. These properties can therefore be used as indicators of soil degradation.