Indicadores microbianos de qualidade do solo em diferentes sistemas de manejo

agricultural activity, by the application of different soil management practices, can cause impacts on soil production capacity that need to be assessed. in this study, different microbiological parameters were evaluated, to assess the relation of soil quality with different tillage practices and crop systems, in comparison to a natural reference soil. the activities of β-glucosidase, urease, acid phosphatase and arylsulphatase were evaluated, as well as soil microbial respiratory activity and microbial biomass. conventional tillage (ct) and no-tillage (nt) were evaluated in two crop rotations and winter fallow. in addition, natural pasture (np) was also evaluated as reference, for comparison with the other management systems. the analyses were carried out in four growing seasons in two years. the results of the four seasons indicated that the enzyme activities, as well as microbial biomass and respiratory activity, were lower in ct than in the other systems, while results in np and nt tended to be similar, indicating the capacity of nt to maintain the original soil quality. on the other hand, the evaluated parameters were in general not significantly influenced by the crop systems.