Determinação da biomassa microbiana como indicador da qualidade do solo

Abstract

The microbial population presented in the soil is extremely plenty and diverse, playing an important role in the decomposition of the organic matter in the soil. Due to the sensibility that the microorganisms show to the physical and chemical changes of the soil, the assessment of the microbial biomass is considered an important index of its quality. The aim of this work was to determine the quality of the soil through physical and chemical parameters and microbial biomass, in samples collected from vegetation areas with passive secondary restoring in early stage (I) and passive secondary restoring in advanced stage (A). The parameters analyzed were organic carbon and total nitrogen, humidity, pH, soil bulk density, carbon and nitrogen of the microbial biomass and microbial enzymatic activity. Based on the experimental results and Turkey tests, it is possible to state that there was a significant difference of 5% between the carbon parameters of the microbial biomass (I= 0,017 g.g-1 e A= 0,028 g.g-1); nitrogen in the microbial biomass (I= 0,23 mg.kg-1 e A= 2,71 mg.kg-1); enzyme microbial activity (I = 1,19 μg FDA.h-1 e A = 1,76 μg FDA.h-1) and moisture (I = 21,92% e A = 29,38%). According to the experimental conditions, it can be concluded that the biological parameters used to determine the soil quality in the study area proved to be efficient with carbon and nitrogen levels in the microbial mass and higher microbial enzymatic activity in the area with secondary restoring in advanced staged, which is justified by the presence of denser vegetation, more abundant tree species, higher shading and higher capacity to retain soil moisture.