Efeitos sazonais e de profundidade sobre alguns parâmetros do solo de uma floresta.

Abstract

The main goal of this paper is to study the effect of wet/dry season and the depth on several parameters of the forest soil. This work has shown that the concentration of Al³⁺ increases and that the concentration of exchangeable cations (Ca²⁺, Mg²⁺) and pHs (distilled water and CaCl₂) decreases with the increase in depth and that these results are correlated. The concentrations of exchangeable cations (Al³⁺, Ca²⁺, Mg²⁺) and organic matter (OM) are affected by dry/wet season. Rain increases the solubility of organic carbon, thus decreasing OM and releasing exchangeable cations (Al³⁺, Ca²⁺, Mg²⁺). P (available) shows an increase in its concentration with an increase in depth. The low concentration of P (available) in the soil samples could be due to the low pH of the soils. The value of pH_pzc is influenced by exchangeable cations (Al³⁺, Ca²⁺, Mg²⁺), and the pHs (CaCl₂ and distilled water) are higher than pH_pzc. This means that the net charge of these soils is negative. CEC and CEC_potential decrease with the increase in depth in most soil samples. For mostly of the samples, the season (wet/dry) does not affect CEC, CEC_potential, K⁺_, or Na⁺.