Changes in Soil Chemical Attributes in an Agrosilvopastoral System Six Years After Thinning of Eucalyptus

The changes in soil chemical attributes in agrosilvopastoral systems after the thinning of trees are unclear. To address this gap, this study evaluated the effects of the thinning of eucalyptus hybrid Urograndis H-13 (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill ex Maiden) on soil chemical fertility in an agrosilvopastoral system in an Arenic Hapludalf in Brazil. The experimental design was a randomized block with a 3 × 4 factorial design comprising three treatments (thinning of 0%, 50%, or 100% of the eucalyptus trees) and four sampling positions relative to the eucalyptus line (0, 2.0, 4.0, and 6.0 m). Six years after eucalyptus thinning, soil acidification was observed in the 0% and 50% eucalyptus thinning treatments, especially at 0 and 2 m from the eucalyptus line. Decreases in soil pH were associated with increases in the total acidity pH 7.0 (H⁺ + Al³⁺) and Al³⁺ content and decreases in the K⁺, Ca²⁺, and Mg²⁺ contents and base saturation over the soil profile (0-1.0 m).