Bioindicadores de qualidade de solos afetados pela exploração de granito.

Abstract

Human actions, such as improper agricultural practices and mineral exploration have been causing soil degradation, and among these, the inadequate management of granite exploration is highlighted in semi-arid regions. The objective was to evaluate the alteration of microbiological indicators of the quality of soils affected by the exploitation of granite in the rural area of Vieirópolis-PB. The design used in the experiment was completely randomized, using three replications. Soil samples were collected from three areas, one being the reference area (AR), never explored; an area where it was explored six years ago, but currently mining remains inactive, (A1), and a third area (A2), which has been operating for the last six years and is currently in full operation. The biological attributes analyzed were constituted by the occurrence and density of actinomycetes, bacteria and fungi, being evaluated through the counting of colony forming units of the method of serial dilutions of soil samples in specific culture media for each group of microorganisms, being used the medium potato dextrose agar plus starch, nutrient agar and potato dextrose agar for each mentioned group, respectively. In all samples studied areas, the occurrence of actinomycetes, bacteria and fungi were detected. The density of bacteria was higher in the three areas studied. Bacteria density was not altered by granite mineral exploration. The densities of actinomycetes and fungi in the areas with the granite mineral exploration process in the soil were lower than in the reference area, indicating that they were affected.