Caracterização granulométrica e química de alguns solos da Estação Cientifica Ferreira Penna (ECFPn)

Abstract

This work is part of the Project "Fluxes and Biogeochemical Behavior of Mercury in Dryland and Floodplain Ecosystems in the Amazon", executed in the area of Caxiuanã by the Emilio Goeldi Museum of Pará in partnership with the Evandro Chagas Institute. The objective of the present work is the morphological, granulometric and chemical characterization of these soils. For this study, three profiles were selected from trenches opened up to 5.0 m deep, at sites that present distinct soil units. In these profiles, designated P2, P3 and P4, the horizons were separated, morphological classification and collection of deformed soil samples. The samples were air dried, crushed and passed through sieves of 2mm mesh. Physical (granulometry) and routine chemical (pH, C, N, P, Ca, Mg, Na, Ke AI) analyses were performed on these samples. At field level, the soils were classified as belonging to the Latosols group. By morphological analysis the soil profiles present a sequence of A, B, and C horizons, with usually diffuse transitions, and the presence of a laterite layer in the B horizon. The wet color of the soil presented variations in hue throughout all profiles, with the 10YR hue being the most predominant. The texture varied from medium (profile P1) to medium and sandy (profiles P2 and P3). The structure also varied from granular to subangular blocks, with a common small to medium size and a strong to weak degree of development. As for the granulometry, a high concentration of coarse sand in relation to the other fractions is noted in all profiles. The distribution profile of most of the chemical elements shows that the contents gradually decrease, highlighting the importance of recycling and incorporation of organic matter on the surface