Soil profiles from three coastal plain regions. I. Morphology, characterization and classification

Abstract

The objective of this work was to characterize morphologically, physically and chemically soils of three regions of the coastal plain in northern part of the Rio de Janeiro state with different vegetation cover, in order to classify them. Lagoa do Robalo (LGR) region showed a profile of Gleyic Podzol with a spodic horizon of humus accumulation. Low differentiated sandy soils were observed at the Canto do Santo Antônio (CSA) region, which was classified as intermediary Luvic Arenosols to Podzol. Such a denomination was proposed in order to emphasize the feeble subsurface accumulation process of fine fractions and organic matter. Campos Novos (CNO) region, with soil profiles classified as well differentiated Podzols, showed subsurface spodic horizon of oxidic material accumulation associated to organic matter. The Gleyic Podzol with Bh horizon found at the LGR region was developed due to the conduction of the inert and porous parent material, high level of groundwater near the soil surface, and native shrubby cover. Except for the superficial horizons, low and subtle differences were imposed by soil cultivation after deforestation of native cover at the CSA region. The soil profile at the CNO region under pasture grass, showed strong depodzolization. The magnitude of the Bshx horizon from the soil profile under native cover is highly affected by an efficient drying process imposed by water absorption of the local forest.