Soil enzymatic activity in Brazilian biomes under native vegetation and contrasting cropping and management

Abstract

Enzymatic activity is a useful indicator for the evaluation of soil biological components. However, a detailed analysis of such indicators in Brazilian soils is lacking. In this study, the activity of soil enzymes was evaluated using data from 73 publications covering 57 locations across all six biomes and eight soil orders out of the 13 that occur in Brazil. The results indicated a wide variation of enzymatic activity in soils, where the means in μg p-nitrophenol g−1 soil h−1 were 569, 116, 112, and 80 for acid phosphatase, alkaline phosphatase, β-glucosidase, and arylsulfatase, respectively. Likewise, values of 148 μg reducing sugars g−1 soil day−1 for cellulase, 57 μg triphenyl tetrazolium formazan g−1 soil day−1 for dehydrogenase, and 38 μg N-NH4+ g−1 soil h−1 for urease were recorded. Soil organic matter and microbial biomass were the best attributes correlated with enzymatic activity, followed by clay content and pH. A more detailed analysis of the acid phosphatase, arylsulfatase, and β-glucosidase activities showed that land-use effects were more pronounced in the Atlantic Forest and Cerrado than in the Caatinga biome. Soils under non-tillage and integrated crop-livestock systems showed higher enzymatic activity than soils under conventional tillage. Soils housing higher biodiversity and delivering higher crop yields also presented higher enzymatic activity, especially in terms of arylsulfatase and β-glucosidase. Enzymatic activity has been shown to be a versatile indicator of soil quality, as it can elucidate how to achieve high-quality standards in tropical and subtropical soils.