Abstract: The objective of this study was to evaluate the organic carbon (OC) distribution and inorganic phosphorus (P) fractions on different soil aggregates classes under forestry fragment of Atlantic Forest, pasture and agroforestry managed for a long period. Soil samples were collected at depths of 0.00-0.10, 0.10-0.20 and 0.20-0.60 m, and the aggregate stability analysis was performed at each depth. The OC and the inorganic P fractions (Pbic readily available, NaHCO3 0.5 mol L-1; PNa1 moderately available, NaOH 0.1 mol L-1; and PNa2 restricted availability, NaOH 0.5 mol L-1) were determined in the respective classes of soil aggregates 4-2, 2-1, 1-0.5, 0.5-0.25 mm. Soil under forestry fragment showed higher OC contents and regardless the land use, highest values of inorganic P were found in the aggregates > 1 mm. Forestry showed highest levels of Pbic, while agroforestry showed the highest levels of PNa1, and pasture had highest values of PNa2.

RESUMO Neste trabalho propôs-se avaliar os atributos químicos e físicos de diferentes coberturas vegetais num Latossolo Vermelho Amarelo no bioma Mata Atlântica, onde foram selecionadas três microbacias de cabeceira, ocupada por pastagem (microbacia P), mata (microbacia M) e cafeeiro (microbacia C). Foram coletadas amostras de solo em três profundidades para caracterização física e química. As características químicas nas diferentes microbacias estudadas apresentaram baixos níveis de fertilidade. Foram observadas a elevação no pH do solo e nos teores de Ca2+ e Mg2+ nas microbacias P e C em relação a microbacia M. Com a retirada da mata e o estabelecimento da agricultura e pecuária houve uma redução dos teores de matéria orgânica do solo nas microbacias P e C, não alterando as características físicas do solo na microbacia P. A implantação da lavoura de café está ocasionando a redução da qualidade do solo na microbacia C em comparação as microbacias P eM, indicando a necessidade de adequação do manejo do solo nesta área.

ABSTRACT The objective of this study was to evaluate the chemical and physical attributes of different soil cover in a Oxisol with a strong wavy relief in the Atlantic Forest Biome, in which were selected three watersheds, employed with grazing (watershed P), forest (watershed M) and coffee (watershed C). Deformed and not deformed samples were collected in three depths for physical and chemical characterization. The chemical characteristics of soil in different watershed studies presented low levels of fertility. It was observed an elevation of pH in the soil and contents of Ca2+ and Mg2+ in the watersheds P and C in relation to the watershed M. Due to deforestation and the establishment of agriculture and livestock, there was a decrease in the contents of soil organic matter in the watershed P and C, not altering the physical characteristics of the soil in the watershed P. The implementation of coffee plantation is causing a reduction in the soil quality of watershed C in comparison to the watershed P and M, therefore indicating a need to adequate soil management in this area.