Little is known bout the pedogenetic differentiation in Alto Paranaíba, western Minas Gerais, Brazil, when materials with such a variety of chemical compositions as tufite, alkaline-ultramafic igneous rocks and carbonatites are compared, which are all found in this region. The purpose of this study was to characterize the physical, chemical and mineralogical properties of three representative soil topolitosequences of the Alto Paranaíba region. Therefore, 11 soil profiles were described and collected in the Serra do Salitre, Patrocínio and Coromandel counties, […]

Copper and zinc adsorption is one of the main phenomena controlling the availability of these metals to plants. As a consequence, studies on the adsorption of such elements in soils may be useful tools to understand the relationship between soil characteristics and retention of these micronutrients. The present study examined the adsorption of copper and zinc in six Latosols (Oxisols) with a wide range of chemical properties. Solutions containing different Cu and Zn concentrations (0, 10, 20, 40, 60, 80, […]

Behavior differences between soils of the South-American and Velhas geomorphic surfaces of the Cerrado region, all of them under native vegetation cover, were evaluated by physical, chemical, and mineralogical characterizations, and principal component analyses. According to their sub-region and geomorphic surfaces, the soils were separated in three groups: 1. clayey to very clayey texture, low- and mesoferric; 2. medium to sandy texture, lowferric; 3. clayey to very clayey texture, ferric. Water retention in the surface horizons of the studied soils […]

Most of the intensely cultivated soils of South Brazil are Brown and Red Ferric Latosols developed from basalt. Typical profiles of these two classes have brown and red hues, respectively, but polychromatic profiles with brown hues in the surface horizons and reddish hues in the subsurface horizons (formerly denominated Brown/Reddish Latosols) also occur. Exact color parameters that separate Brown and Red Latosols are not yet defined in the Brazilian Soil Classification System. All these soils are clayey and have high […]

Nutrient transport to roots is basically performed by mass flow and diffusion. As the nutrients in the mobile solution (inter-aggregate solution) are depleted, they move by diffusion from the interior to the aggregate surface. This study quantified Mg, Ca, and K in effluents from aggregates of a Brazilian Rodhic Haplustox, in relation to diffusion time, using distilled water as eluate. Treatments were established in a 4 x 5 factorial scheme: four aggregate classes (2.0-1.0, 1.0-0.5, 0.5-0.25, and 0.25-0.105 mm) and five diffusion times […]

Soil landscape position is important in relation to the amount of stored and available water for the plants. The cohesive layer in the tableland soil of the Northeast of Brazil hinders the water flow in the profile. During rainy periods, the formation of transitory water tables above cohesive horizons is possible, due to the restriction of descending vertical flow caused by such horizons. Therefore, the occurrence of interflow (downhill lateral subsuperficial water flow) on the cohesive horizons in slope areas […]

A micropedological study was carried out in rehabilitated soils after bauxite mining, in sites dating from 1981 to 1987, compared with the Yellow Latosol, as reference, to subsidize soil indicators of rehabilitation. The study was located in Porto Trombetas, district of Oriximiná, northwestern Pará State. Micromorphological techniques, using EDS/SEM microprobe, optical and scanning electronic microscopy, were used in combination with chemical and physical analysis, at 0-10 and 40-50 cm depths. The Yellow Latosol showed a strong development of microgranular structure, […]

Little is known about the effect of mafic parent materials on soil genesis in the humid “Zona da Mata”, Minas Gerais, although there are many detailed studies on soils developed from felsic to mesocratic gneiss, notably Latosols and terrace Podzolic soils. To fill this gap, soils in two topolitosequences, comprising A and B or A and C horizons, were sampled and studied. In the first topolitosequence, at Serra de Guiricema, a Red-Yellow Latosol on the top, a Argilluvic Chernosol, a […]

The spatial variability of strongly weathered soils under sugarcane and soybean/wheat rotation was quantitatively assessed on 33 fields in two regions in São Paulo State, Brazil: Araras (15 fields with sugarcane) and Assis (11 fields with sugarcane and seven fields with soybean/wheat rotation). Statistical methods used were: nested analysis of variance (for 11 fields), semivariance analysis and analysis of variance within and between fields. Spatial levels from 50 m to several km were analyzed. Results are discussed with reference to […]

The quality of semi-detailed (scale 1:100.000) soil maps and the utility of a taxonomically based legend were assessed by studying 33 apparently homogeneous fields with strongly weathered soils in two regions in São Paulo State: Araras and Assis. An independent data set of 395 auger sites was used to determine purity of soil mapping units and analysis of variance within and between mapping units and soil classification units. Twenty three soil profiles were studied in detail. The studied soil maps […]