Microbial enzymatic stoichiometry and the acquisition of C, N, and P in soils under different land-use types in Brazilian semiarid

Abstract

This study hypothesized that different land-use affect the microbial enzymatic stoichiometry and C-, N-, and P-acquisition in Brazilian semiarid soils. Thus, the enzymes β-glucosidase (C-acquiring enzyme), urease (N-acquiring enzyme), and acid phosphatase (P-acquiring enzyme) were assessed in soil samples collected at 0–5 and 5–10 cm depth from a tropical dry forest, a protected area with Angico, a protected area with Ipê, scrub area, and an agricultural area with maize. The values of C-, N-, and P-acquiring enzymes were used to calculate the enzymatic C:N, C:P, and N:P ratios. The values of C:P and N:P ratios were higher at 0–5 cm depth, while no significant variation, between soil depth, was observed for C:N ratio. The values of C- and N-acquiring enzymes were higher at 0–5 cm in tropical dry forest areas and Angico forest, respectively. In all land use types, the values of vectors L and A were higher than 1° and 45°, respectively. This study showed that both land-use and soil depth influence the enzymatic stoichiometry, showing higher values of C- and N-acquiring enzymes in native and protected forests at soil surface.