ABSTRACT Soils in the Depressão Central and Campanha Gaúcha in Rio Grande do Sul State, Brazil, developed from sedimentary rocks are mainly Alfisols (Luvissolos, Planossolos and Plintossolos) and Ultisols (Argissolos) with high textural contrast between A and/or E horizons and clayey B horizons. Red Ultisols dominate in well-drained areas in the summit. But many soils present redoximorphic features on the backslope and footslope, with mottled and/or nodules similar to plinthite due to the oscillating of the water table above the […]

ABSTRACT Plinthite and petroplinthite occur frequently in Brazilian soils, but there is little information on the behavior of these materials. The aim of the present study was to assess the effect of different drying periods on the hardening and stability of plinthic materials of soils in the floodplain of the Araguaia River and the João Leite stream in Goiás. Soil samples were collected, with the aid of 0.10 m high and 0.15 m diameter PVC cylinders, directly from the plinthic […]

The objective of the study was to characterize and classify four Plintosols (Ultisols and Entisols with plinthite) in Pinheiro county, Maranhão state (Brazil), to validate the new classes proposed in the Brazilian System of Soil Classification (SiBCS). Four pedons were selected in different hill slope positions: shoulder, backslope, footslope, and toeslope. The parent material consisted of ferruginous sandstone of the Itapecuru Formation and colluvial and alluvial sediments. Soil profiles were morphologically described and each horizon analyzed for physical, chemical and […]

Little is known about chemical and mineralogical attributes of soils from the upper Amazon, compared with well-studied soils from the middle and lower Amazon. In the well-drained uplands of Upper Amazon, due to the Andes Cordillera proximity, soils are expected to be chemically richer. This work aimed to increase the knowledge of soils from the upper Amazon, by means of studying three soils along a typical topossequence at Benjamin Constant, near the Brazilian-Peruvian Border. These soils range from the uplands, […]

In northern and western landscapes of São Paulo State, plinthite and petroplinthite are features observed commonly above the cretaceous Adamantina Formation sandstones (Bauru Group). Two representative soil profiles with plinthic, petroplinthic and mottling features were selected in the local landscape to evaluate the mineralogical characteristics and to study their formation. The study was carried out at the foot of a mountainside in the Experimental Station Pindorama of the Agronomic Institute Campinas (IAC), in the north of São Paulo State, Brazil. […]

Plinthite and petroplinthite are commonly present features in soils developed on sandstone of the Bauru Group, Adamantina Formation, in the northern and western region of São Paulo State. The objective of this study was to evaluate chemical properties as well as pedogenic processes that led to the formation of these materials and the soil profile. Two soils at the foot of a representative mountainside of the local landscape with plinthic, petroplinthic and mottling features were selected within areas of the […]