tividade e densidade microbiana em sistema agroflorestal agroecológico, cultivo convencional e remanescente florestal

Abstract

The study of biological attributes and indicators can provide crucial data for proper land use planning, as it takes into account the dynamic nature of microorganisms in the soil. The present work aimed to evaluate microbial activity and density in an agroforestry system compared to a conventional cropping system. Soil samples were collected in the agroecological agroforestry system "Dona Dora" located at the Federal University of Mato Grosso - Sinop/MT campus and in two areas adjacent to the agroforestry system, but with different land use systems: I) forest remnant and II) conventional cropping. In each area, composite samples were collected with four repetitions, at a depth of 0 to 10 cm. Microbial biomass carbon, soil basal respiration, metabolic quotient, total bacterial and fungal counts, and associative nitrogen fixing bacteria were evaluated. The results obtained were submitted to normality test and analysis of variance (ANOVA), the means were compared by the Scott-Knott test at 5% significance level. The agroforestry system area showed the highest total fungal and bacterial counts and associative nitrogen fixing bacteria. Microbial biomass carbon and soil basal respiration did not differ among the three areas evaluated. The metabolic quotient presented the highest value in the area with conventional cultivation, and the lowest value in the agroforestry system and forest remnant. Thus, it is concluded that the agroforestry system influences the population and microbial activity, favoring the establishment and greater efficiency in the use of carbon by microorganisms.