Correlations between enzymatic activities and microbiological parameters in lacustrine and alluvial soils of Venezuela under different land use

The aim of this study was to evaluate the possible correlations between some soil microbiological parameters (basal respiration, microbial biomass carbon) and the activity of certain enzymes involved in the cycles of C, N, and P, to determine if the latter could be considered indicators of microbial activity in alluvial and lacustrine soils of the Valencia Lake Basin (Venezuela) under different land use. Activities of β-glucosidase, urease, protease, acid and alkaline phosphomonoesterase, dehydrogenase, and arginine ammonification were determined in soils under natural vegetation, sugarcane cultivation, and banana cultivation. Positive and significant correlations were found between enzymatic activities and microbial biomass carbon and basal respiration, as well as with total organic carbon content, water-soluble carbon, and the physical and chemical properties of the soil. Protease activity showed the highest correlation coefficient with microbial biomass carbon. Acid phosphomonoesterase activity had the highest coefficient with respect to basal respiration, and alkaline phosphomonoesterase correlated most strongly with dehydrogenase activity and arginine ammonification. The correlation coefficient between β-glucosidase activity and total organic carbon content was the highest compared to those of all hydrolases evaluated. These findings suggest that enzymatic activities can serve as reliable indicators of microbial activity in the studied soils. Significant positive correlations between biological parameters and total organic carbon further indicate a close relationship between microbiological activity and soil organic matter content.