Enzyme activities in cerrado soils of brazil

Enzymes play an important role in cycling of organically bound nutrients in soils. Pyrophosphatase (PPi), acid phosphatase (AP), arylsulfatase (AS), urease (UR), and dehydrogenase (DH) activities were measured in air-dry samples from the top 15 cm of two dark red Latosols and four red-yellow Latosols from Cerrado regions of Minas Gerais (MG) and Goias (GO) Brazil. Relationships between enzyme activities and soil properties were examined. Among the six soils, the dark red Latosol from Sete Lagoas, MG, had;the highest activities for AP, AS, and UR enzymes. The lowest activities for these enzymes were observed in a dark red Latosol from Uberaba, MG, and this soil also recorded the lowest DH activity. The red-yellow Latosol from Sete Lagoas, MG, had the highest PPi and DH. The activities, whereas a red-yellow Latosol from Felixlandia, MG, gave the lowest PPi activity. Activities of all enzymes were negatively correlated with sand and silt content and positively correlated with clay content. Overall, the enzyme activities were positively correlated with pH, organic carbon (C), Bray P, and exchangeable potassium (K), calcium (Ca), and magnesium (Mg). Soil organic C appears to have the greatest effect on the level of enzyme activities in acid soils. Each soil type has its own inherent levels of enzyme activities. Knowledge of relationships between enzyme activities and soil properties could be useful in development of sound fertilizer practices for Cerrado soils.