The geochemical behavior of trace elements (TE) and rare earth elements (REE) was evaluated in the region of Lavras (MG), during the pedogenetic evolution in soil profiles with argillic horizons differentiated by acid, intermediate and basic compositions of the parent material.Chemical analyses of TE and REE were performed along the profiles and gains and losses were evaluated through mass chemical balance.The study allowed to group the TE into two classes: (a)moderate to high mobility: loss from the consolidated rocks to […]

The objectives of this study were to evaluate the parameters from isotherms of Freundlich and Langmüir that best reflect the adsorption of heavy metals in weathered soils, and to identify the relationship between the selected parameters and the chemical, physical and mineralogical attributes of twelve representative soil classes from Brazil.The soils were collected by EMBRAPA-CNPS during various surveys in the Southern, Southeastern and Northern areas of Brazil.The correlation coefficient among dependent variables, obtained through the isotherms of adsorption (parameters of […]

Black oat/corn succession has been commonly used in the south of Brazil and N fertilization management is important for its success, especially under no-tillage. This study was carried out at the experimental area of the Department of Soil Science, at Federal University of Santa Maria (RS), Brazil, during 1999/2000, using a Hapludalf (sandy loam/clay loam).The objective was to evaluate the possibility to transfer, partially or totally, the amount of N, normally sidedressed to two applications – black oat tillering and […]

The objective of this study was to evaluate the effects of P rates and placement on P uptake, leaf P use efficiency (PUE), and grain yield of corn (Zea mays) grown in a Yellow Argissol soil, typical of the coastal tablelands.Rates of 0, 45, 90, 135 and 180kgha-1 of P2O5 were applied in either the rows or broadcast.The study was carried out during the rainy season, from June to September of 1998, at Umbaúba Experimental Station, at Umbaúba (SE), Brazil.Broadcast […]

Natural grassfields developed on sandy soils from Northern Uruguay are formed by communities of forage species, composed mainly of seasonal growing grasses, with low biomass production during the fall/winter period. The objective of this study was to evaluate the effect of herbicides, applied on native grassfield to established winter forage species, on soil properties and root biomass. This experiment began in 1994 and was established as a complete block design, with three replications. In the main plots, to establish winter-growing […]

Acid drainage, resulting from sulfide oxidation, is an environmental problem which may impair soil and water sources quality. Such impact may occur in several environments, but it is commonly related to coal mining. This work was carried out to study the kinetics of pyrite oxidation in coal mining spoil from Candiota (RS) Brazil, under different conditions of atmospheric O2 access and pH. The study aimed to evaluate the possibility of adjusting carbonate dissolution rate to the sulfide oxidation rate in […]

To investigate the mineralogical variations with depth, 11samples were collected down to 14m, in an exposed sediment packet of the Barreiras Group in Aracruz, Espírito Santo, Brazil.The sand, silt and clay fractions were studied by X-ray diffraction, differential thermal analysis, thermogravimetry and electron microscopy.The total contents of Fe in the clay and silt fractions and Ti and Zr in the silt fraction were determined by ICP after fluoridric acid extraction.Clay and silt fractions were submitted to selective and sequential mineral […]

Detailed chemical and crystal properties of the kaolinite (Ka) and iron oxides in the Barreiras Group soils and sediments (Coastal Tablelands) are little known. Eleven samples were collected (0,7; 1,4; 2,1; 2,8; 3,5; 4,2; 4,9; 5,6; 7,7; 10,5 and 14m) in an exposed sediment sequence in Aracruz, Espírio Santo State, Brazil, in order to study the characteristics of these minerals with depth. Clay and silt fractions were studied by X-ray diffraction (XRD), differential thermal analysis and electron microscopy. Total contents […]

The use of green manure to establish diversity and equilibrium of a crop system is one of the paragons in modern agriculture.Soil samples and green manure species intercropped with maize were evaluated in a field experiment, from 1995 to 1997, carried out in an Aleudalf Soil, located in Piracicaba (SP)Maize seeds were planted at 0.90 meter spacing within lines totaling 50,000 plants per hectare.The treatments were performed with four green manure species: dwarf mucuna (Mucuna deeringiana (Bort.) Merr), dwarf pigean […]

An experiment was carried out at the Soil Science Department of Federal University of Lavras (MG), from November/1999 to January/2000, aiming to evaluate the survival of strain and isolates of rhizobia, in heavy metal contaminated soil.The possible relationship between rhizobia tolerance in culture medium and its survival in contaminated soil was also verified.From a group of 60strains/isolates tested at a previous study for metal tolerance in YMA medium, two out of the most tolerant microorganisms [BR-4406 (strain recommended as inoculant […]