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 […]

Maximum liming efficiency depends not only on the quality of the corrective material but also on appropriate incorporation according to depth and homogeneity.Based on this, this work aimed to evaluate the effect of limestone incorporation ways on the production of black oat and on the correction of acidity in soil profile.An experiment was carried out in a Typic Acrustox loamy texture, in the area of the Triângulo Mineiro in Uberlândia (MG) from May 1995 to February 1996.The experiment was arranged […]

This study was carried out at EMBRAPA-CNPAF, Santo Antônio de Goiás (GO), Brazil, in a clayey Oxisol, under three soil tillage systems, from 1992 to 1998.Corn was grown in the summer and common bean in the winter, under center pivot sprinkler irrigation.The objective was to compare the values of pH, Ca, Mg, P, and K of the soil, sampled at different depths under no-tillage to those from soil under moldboard plough tillage (conventional) and harrow tillage.Forty replicates were collected at […]