Volume 33, Number 6, 2009

The potential for adopting crop-livestock systems in southern Brazil is high, especially in untilled soybean areas with cover crops in the winter season. The long-term use of this system at different grazing intensities will result in different carbon and nitrogen stocks in the soil due to the different plant and animal residues. This research was conducted to evaluate alterations in total carbon and nitrogen pools and in organic matter fractions in a soil under different grazing intensities under no-tillage. The […]

Different management systems tend to modify soil structure and porosity over the years. The aim of this study was to study modifications in the morphostructure and porosity of dystroferric Red Latosol (Oxisol) under conventional tillage and no-tillage over a 31- year period. The study began with the description of soil profiles based on the cropping profile method, to identify the most compact structures, define sample collection points for physical and chemical analysis, and determine the water retention curve. A forest […]

Despite the increasing number and diversity of publications related to soil erosion in Brazil and throughout the world, the central questions of this science remain unanswered. The possible reasons for this imbalance highlight the need to reconsider the role of research on soil erosion. Bibliometric studies can provide ample view of the research field, describing perspectives, but research using this approach is scarce in international as well as in Brazilian literature. The objective of this study was to analyze the […]

The current high price of KCl and great dependence on importation to satisfy the Brazilian demand indicate the need for studies that evaluate the efficiency of other K sources, particularly those based on domestic raw material. For this purpose, a greenhouse experiment was conducted with samples of a sandy clay loam Typic Haplustox, in a completely randomized 4 x 3 x 2 factorial design: four K rates (0, 60, 120, and 180 mg kg-1), three sources (potassium chloride (KCl), fused […]

Organic residue application into soil alter the emission of gases to atmosphere and CO2, CH4, N2O may contribute to increase the greenhouse effect. This experiment was carried out in a restoration area on a dystrophic Ultisol (PVAd) to quantify greenhouse gas (GHG) emissions from soil under castor bean cultivation, treated with sewage sludge (SS) or mineral fertilizer. The following treatments were tested: control without N; FertMin = mineral fertilizer; SS5 = 5 t ha-1 SS (37.5 kg ha-1 N); SS10 […]

The residues of swine production have a great potential as soil chemical conditioners for crop production The purpose of this study was to evaluate: (a) corn yield, after application of swine manure and increasing doses of soluble copper in an Eutroferric Red Latosol with two organic matter contents (34,09 and 8,60 g dm-3), (b) the influence of soil copper and organic matter content on copper absorption and translocation to corn shoots. The study was set up in a greenhouse of […]

Phytoextraction has been suggested as a viable alternative to traditional restoration practices for heavy metal-contaminated soils (e.g., soil removal and disposal in land fill areas, or co-processing in cement), in view of the lower costs and lower environmental impact. This study had the objective of evaluating induced phytoextraction (use of chelating agent) of heavy metals in black oat (Avena strigosa Schreber), sunflower (Helianthus annuus L.) and Bahiagrass (Paspalum notatum Flügge) in polluted soils (soils 2, 3, and 4) of a […]

The forms and availability of heavy metals in contaminated soils determine the uptake potential of plants and water contamination by leaching. In this study different methods of chemical extraction were used, in order to identify the forms of Pb, Cd, Cr, Ni, Cu, and Zn and evaluate the availability of these pollutants for sunflower (Helianthus annuus L.), black oat (Avena strigosa Schreber) (exotic species) and Bahiagrass (Paspalum notatum Flügge) (native species), as indicators, in soils of Pb mining and metallurgy […]

Phosphorus fertilizers are intensively used in Brazil, since the low availability of phosphorus often limits yields in tropical soils. However, these fertilizers can be a entranceway for soil contamination with heavy metals. This study was carried out to investigate heavy metal contamination caused by the application of five different phosphorus fertilizers as well as the metal uptake by corn (Zea mays) plants. The fertilizers simple superphosphate, triple superphosphate, Araxá rock phosphate, Yoorin thermophosphate, and Gafsa rock phosphate were applied at […]

The environmental impacts resulting from uranium exploration and processing are to a great extent identical to those caused by extractive mining activities in general. This study aimed to determine the geochemical partitioning of the natural radionuclides 238U, 226Ra and 210Pb in areas surrounding the Uranium Mining and Concentration Plant (URA) of the Brazilian Nuclear Industries S.A., in the uranium deposit region of Lagoa Real, in Caetité, southwestern Bahia state. Representative soil samples of the main regional soil classes were collected […]