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 formation of soils with argillic horizons was investigated to identify the pedological processes involved in the formation of lamellae and the abrupt textural gradient as well as their implication on the soil physical, chemical and mineralogical attributes. This study was carried out on a sandstone-derived soil toposequence, with profile (P1) occupying the higher part of the landscape (summit), profile (P2) on the backslope, and profile (P3) on the footslope. Soil chemical, mineralogical, micromorphological and particle size distribution analyses were […]

On the landscape of the Eastern Plateau, north of the State of São Paulo, Brazil, there are ferricretes in different elevations. Although these features are relatively frequent over the cretaceous sandstone (Adamantina Formation, Bauru Group), little investigation has been carried out on their genesis. A morphological study at different levels of observation was conducted in order to elucidate the genesis of ferricretes (plinthite and petroplinthite), occurring at the toeslope of a landscape where soils with argillic horizon predominate, at the […]

This experiment was carried out in pots containing a Dark Red Latosol (Acrortox, loamy sand), to evaluate the effect of sub-soil compaction on root growth of six cover crop species (black oats, pigeonpea, pearl millet, black mucuna, sorghum and blue lupin). The treatments consisted of three sub-soil compaction rates at a 15 cm depth, where bulk densities of 1,12, 1,36 and 1,60 Mg m-3 were established. Cover crop species were grown for a period of 37 to 39 days after emergence, when they were […]

Soil tillage and consolidation modify soil resistance to rill erosion. Thus, an experiment was carried out on a Hapludulf, under field conditions in 1997/98, to study rill erosion under different tillage methods and soil consolidation, to evaluate the sediment size and to determine rill erodibility (Kr) and critical shear stress (τc). The experiment was completely randomized with six replications, using the following treatments: recent conventional tillage (RCT), two-month consolidated conventional tillage (CCT), no-tillage with mulch (NTM) with 94% surface coverage […]

Rainfall characteristics may determine most of the harmful effects of soil erosion. Intensity variation during a rainfall is one of these important rainfall characteristics. However, there is a lack of information about rainfall patterns that occur in Brazil. This research had as objectives the determination of natural erosive rainfalls patterns verified in Santa Maria (RS), and the estimation of rainfall return period for the three patterns proposed. Daily rainfall charts were obtained from the Research Center of Forestry and Soil […]

Total soil lead (Pb) content along with the sorption capacity of Pb in soils are important parameters for risk assessment studies of Pb in the environment. This experiment used A-horizon samples of 17 Oxisols from all Brazilian regions to evaluate their total Pb content as well as their Pb maximum adsorption capacities (PbMAC). The total soil Pb content varied from 6.14 to 30.55 mg kg-1, averaging 18.00 mg kg-1. The highest total soil Pb contents were found for soils of the southern and southeastern regions, […]

An experiment, covering 12 cultivations, was carried out at Embrapa Rice & Beans Research Center, Santo Antônio de Goiás, Goiás, Brazil, in an Oxisol under center pivot, for six consecutive years. The effects of four soil tillage systems and six crop rotations on pH in water, exchangeable Al and Ca + Mg, organic matter, extractable P, and exchangeable K were evaluated, using a completely randomized design, in a splitplot arrangement, with three replications. The tillage treatments were: moldboard plough/harrow disc, moldboard plough, […]

Soil and water loss under natural rainfall in Lages (SC – Brazil), from November 1992 to October 1998, were used to calculate soil loss ratio (SLR) and C factor for the Universal Soil Loss Equation (USLE) under three soil tillage systems and two crops. Treatments studied were plowing followed by two disking (P+D), chiseling plus disking (C+D) and no-tillage (NT), cultivated in succession with soybean (Glycine max) and wheat (Triticum aestivum L.), compared to a check plot: plowing followed by […]

The objectives of this work were to assess soil and water losses and determine interrill erodibility (Ki) of three soils with clayey texture: Typic Rhodudult (PE), a Typic Hapludult (PV) and a Rhodic Hapludox (LR) for the application of the WEPP (Water Erosion Prediction Project) model in Lavras, Minas Gerais, Brazil and to evaluate the relationship between Ki and some physical, chemical and mineralogical soil properties and surface characteristics. The experiment was set in a completely randomized block design, consisting […]