Seasonal variation of soil attributes in oil palm plantations in the Eastern Amazon

Brazil stands out worldwide in the production of oil palm; however, there is a need to understand the interaction between the plantations and the environment. The objective was to evaluate the microbiological and chemical attributes of the soil in plantations of different ages of oil palm and of a secondary forest in two seasonal conditions. The microbiological variables analyzed were the carbon of the microbial biomass (C-BMS), total carbon (C-TOTAL), total nitrogen (N-TOTAL), basal respiration (RB), metabolic quotient (qCO(2)), carbon / nitrogen ratio (C/N) and gravimetric humidity (Ug); (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), effective cation exchange capacity (CTC) and aluminum saturation (% m). The chemical attributes of soil fertility and soil microbial biomass presented stronger and larger correlations in the rainy season. The most sensitive microbiological attributes to age of oil palm were C-BMS, qCO(2) and C/N ratio, while the chemical variables were P, Ca, Al, CTC, and pH in water.