280 results

Influence of digestion methods on the recovery of Iron, Zinc, Nickel, Chromium, Cadmium and Lead contents in 11 organic residues

Thalita Fernanda Abbruzzini, Carlos Alberto Silva, Daniela Aparecida de Andrade, Waldete Japiassú de Oliveira Carneiro

01/Feb/2014

There are currently many devices and techniques to quantify trace elements (TEs) in various matrices, but their efficacy is dependent on the digestion methods (DMs) employed in the opening of such matrices which, although “organic”, present inorganic components which are difficult to solubilize. This study was carried out to evaluate the recovery of Fe, Zn, Cr, Ni, Cd and Pb contents in samples of composts and cattle, horse, chicken, quail, and swine manures, as well as in sewage sludges and […]

Influence of mineral fertilization on edaphic fauna in Acacia auriculiformis (A. Cunn) plantations

Liliana Parente Ribeiro, Emanuela Forestieri Gama-Rodrigues, Maria Kellen da Silva Moço, Antonio Carlos Gama-Rodrigues

01/Feb/2014

Fertilization and/or the accumulation of organic matter from plant residues can influence the composition of soil and litter community. The goal of this study was to evaluate the effects of P and K fertilization on total faunal and nematode faunal composition and richness in plant litter and soil for 360 days in an area reforested with Acacia auriculiformis (A. Cunn), located in the municipality of Conceição de Macabu in the State of Rio de Janeiro. For each treatment (fertilized and […]

Eisenia andrei (Oligochaeta) as bioindicator of soil contamination by hexachlorobenzene (HCB)

Thaís Mitre Vampré, Raffaella Fuccillo, Mara M. de Andréa

01/Feb/2010

HCB (hexachlorobenzene) is an environmentally ubiquitous organochlorine compound and is classified as one of the persistent organic pollutants (POP). It is highly toxic and has been found in the region “Baixada Santista” of the state of São Paulo (Brazil) for a number of years. To evaluate the potential of the earthworm species Eisenia andrei as bioindicator of HCB-contamination, earthworm specimens were maintained for 14 days in soil containing 14C-HCB, and their bioaccumulation was analyzed. No mortality was detected after neither […]

Soil organic matter in highland Leptosols: influence of pasture management on composition and content

Mariana da Luz Potes, Deborah Pinheiro Dick, Ricardo Simão Diniz Dalmolin, Heike Knicker, Alessandro Samuel da Rosa

01/Feb/2010

Burning pastures after the winter is a traditional practice in highland soils, whose main purpose is the regrowth of vegetation. However, the impact of fire, as well as the influence of grazing on the organic matter of Leptosols is still unknown. The purpose of this study was to investigate the composition and content of organic matter in soil profiles from São José dos Ausentes, state of Rio Grande do Sul, and to relate the results with the occurrence of burning […]

Spatial and temporal variability of crop yield and some Rhodic Hapludox properties under no-tillage

Osvaldo Guedes Filho, Sidney Rosa Vieira, Márcio Koiti Chiba, César Hideo Nagumo, Sônia Carmela Falci Dechen

01/Feb/2010

Soil properties are closely related with crop production and spite of the measures implemented, spatial variation has been repeatedly observed and described. Identifying and describing spatial variations of soil properties and their effects on crop yield can be a powerful decision-making tool in specific land management systems. The objective of this research was to characterize the spatial and temporal variations in crop yield and chemical and physical properties of a Rhodic Hapludox soil under no-tillage. The studied area of 3.42 […]

Movement of a solute applied in two concentrations to an unsaturated soil via a disk permeameter

E. Borges, P. L. Libardi

01/Jun/2002

Groundwater pollution is one of the main factors justifying the study of soil solute movement and the processes of soil solute interaction. A deeper penetration than the expected of the chemicals applied to the soil surface, together with laboratory observations of the decrease of the amount of solutes in the solution passing through the soil, led researchers to consider the soil water (or solution) as having two phases: a mobile phase, θm, and an immobile phase, θim. In this paper, […]

Iron oxidation on roots of two rice cultivars in flooded soil solution

G. Nava, H. Bohnen

01/Jun/2002

Rice cropped under waterlogged conditions may present symptoms of nutritional disorders similar to those caused by iron (Fe) toxicity. The symptoms do not occur in the same intensity in all cultivars and are more frequent in modern cultivars. The aim of our study was to evaluate the plant capacity of oxidizing reduced iron (Fe2+)on the root surface in green house conditions, comparing two rice cultivars (BR IRGA 409 and EPAGRI 108) with different degrees of susceptibility to iron toxicity and […]

Relationship between heavy metals adsorption and chemical and physical attributes of soil classes from Brazil

W. S. Araújo, N. M. B. Amaral Sobrinho, N. Mazur, P. C. Gomes

01/Mar/2002

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 […]

Factors controlling compressibility of a paleudalf and a haplortox soil. I- initial state of compactness

V. R. Silva, D. J. Reinert, J. M. Reichert, J. M. Soares

01/Mar/2002

Knowing the susceptibility of a soil to compaction is important to adjust soil management, tillage practices, and traffic to cause minimal detrimental effects on soil properties. The objective of this study was to determine the preconsolidation pressure (σ’p) and the compression index (Cc) at two depths of two soils under no-tillage and conventional tillage, including a wide variation of the state of compaction. Undisturbed soil samples were collected with rings (5.4cm wide and 2.0cm high), at 0 to 2 and […]

Vesicular arbuscular mycorrhizae fungi in soils polluted with heavy metals

O. Klauberg-Filho, J. O. Siqueira, F. M. S. Moreira

01/Mar/2002

The arbuscular mycorrhizal fungi (AMF) are ubiquitous establishing symbiosis with a large number of plants in spite of soil contamination with heavy metals.This study aimed to evaluate AMF occurrence and diversity in soils of four locations cultivated with grass species and contaminated with heavy metals as a result of Zn extraction and industrialization. AMFs were found in all locations, with species predominance being affected by heavy metal concentration in soil. Twenty one species were identified, belonging to the following genus: […]

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