Volume 28, Number 4, 2004

In the Lakes Region of Rio de Janeiro State, the occurrence of a drier climate creates a peculiar environment where there is a trend of salinization and presence of xeric vegetation. Physical, chemical, mineralogical and micromorphological properties were studied in selected soil transects. The soils are eutrophic as result of nutrient cycling, low weathering degree, and presence of primary minerals with nutrient reserves in their composition. The occurrence of well developed eutrophic soils (Oxisols) under caatinga (xeromorphic vegetation) on the […]

This study defines some aspects of superficial alteration processes and their reflexes on the Quaternary pedogeomorphology in the sub-basin of the upper Maracujá River, in the Complexo Bação, ferriferous zone, State of Minas Gerais, Brazil. Characteristics related to the dynamic evolution of three gneiss-underlayered toposequences (1, 2, and 3) at different erosion stages were investigated. In the top slope segments of the toposequences 1 and 2 the soil profiles are little developed and present an in situ evolution. In toposequence 3, […]

Conservational management systems increase the content of soil organic C and N. However, their effects on the light fractions of the soil organic matter (SOM) are not very well known, particularly under tropical climate conditions. The objective of this study was to evaluate the effect of soil tillage systems on the distribution of light fraction (free and intra-aggregate) organic matter in a Red Latosol (Rhodic Haplustox) cultivated with vegetable crops. The study site was located in Paty do Alferes (Rio […]

The dynamics of nitrogen in soils under no-tillage in Southern Brazil are poorly studied so far. A field experiment on a typic Hapludalf on the experimental area of the Soil Science Department, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil, was carried out in 1998/99 and 1999/00 to evaluate the effect of single crop and mixtures of black oat (BO) (Avena strigosa Schieb), common vetch (CV) (Vicia sativa L.) and oilseed radish (OR) (Raphanus sativus […]

No-tillage has been increasingly adopted by farmers in South Brazil and it has increased the interest for the mixtures of cover crops in the autumn/winter as source of nitrogen to the corn in succession. A field experiment was carried out on a typic Hapludalf at the experimental area of the Soil Science Department, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil, in 1998/99 and 1999/00 to evaluate the effect of single crop and mixtures of […]

Different management practices lead to distinct surface and subsurface soil physical conditions, which in turn result in different levels of rainfall erosion. In this context, a 5.5 year field erosion-study was conducted with the objective of studying the effects of both tillage and cropping systems and forms of crop residue management on some surface and subsurface physical soil conditions and their influence on rainfall erosion. For this purpose, rainfall was simulated on a severely degraded, sandy loam Paleudult with 0.08 m m-1 […]

The effects of lime rates on the growth of Eucalyptus camaldulensis in soil mixtures with increasing proportions of Zn and Cd contamination were evaluated. The experiment was carried out under greenhouse conditions and the metal contamination levels were obtained by mixing 0, 25, 50, and 100% of a contaminated soil with a non-contaminated one used as diluter. Lime rates were 0, 10, 20, 40, and 80 t ha-1 and the experiment was conducted in pots containing 1.5 kg of soil with treatments arranged […]

The objective of this research was to determine the heavy metal concentration in soils of a topolithosequence in western Minas Gerais State, in order to evaluate their potential availability in soils originated from distinct parent materials. Seven soil samples were collected, air dried, and sieved through a 2 mm sieve and then had their Cd, Cu, Pb, and Zn contents determined. The total concentration of the chemical elements was assessed using HNO3/HClO4 extractant (4:1 by volume). The soluble forms were analyzed […]