Atividade enzimática como indicador de qualidade do solo em sistema de manejo em floresta tropical seca do semiárido brasileiro

Abstract

Biochemical attributes play a very important role in biogeochemical cycles of elements, which is essential for the survival of living beings. Thus, knowledge about the enzymatic activity contribute to assess the quality of the use or soil management. This study aimed to 1. determine the activity of the enzymes involved in phosphorus, sulfur and nitrogen cycle in the surface layers of soil in areas at different times of stages of forest regeneration in the city of Forest-PE and 2. evaluate the enzymatic activities in the Cambisol, Planosol and Oxisol profile, up to 1m deep, in areas under forest regeneration stages. In a homogeneous solo track, six areas were selected according to the cutting times of caatinga vegetation of forest management established for each area: C-18: vegetation regeneration for 18 years; P-13: 13 years ago; L-12: 12 years ago; 9- C: 9 years ago; C- 7: 7 years ago and L- 4: 4 years ago. In six areas, samples were taken at depths of 0-5, 5-15 and 15-30 cm for the evaluation of enzymes acid and alkaline phosphatase, arylsulfatase and urease. These six areas studied, three of these (P-13, C-9 and L-4) were open profiles and samples collected at depths 0-5, 5-10, 10-20, 20-40, 40-60, 60-80 and 80-100 cm for evaluation of the parameters described above. Biochemical parameters were sensitive in detecting changes in soil quality in tropical dry forest. The activities of enzymes acid and alkaline phosphatase, arylsulfatase and urease decreased with increasing soil depth. The Planosol was the profile that showed higher enzyme activities, at all depths, for acid and alkaline phosphatase enzymes.