Consulta: subjectFacets:"Exchangeable cations"
Registros recuperados: 4
Data/hora: 03/06/2024 05:19:47

Alterações na matéria orgânica e nas características químicas de um Podzol hidromórfico sob pastagens cultivadas no Pantanal Sul-Mato-Grossense.
Provedor de dados: Informação Tecnológica em Agricultura (Infoteca-e)
Autores: FERNANDES, F. A.; CERRI, C. C.; FERNANDES, A. H. B. M.
Estudou-se uma cronosseqüência de introdução de pastagens cultivadas em áreas com 10 e 20 anos de implantação, tendo uma área de Cerrado intacto como referência. Coletaram-se amostras até 40cm de profundidade ao longo de dois transectos, para cálculo dos estoques de C e N e determinações químicas. Também abriram-se trincheiras e coletaram-se amostras de solo até 1m de profundidade, para estudo das variações nos conteúdos de C e N no perfil. Após 10 anos de cultivo, o solo apresentou aumento no teor de bases trocáveis e na capacidade de troca catiônica, e diminuição da acidez. Entretanto, após 20 anos, os teores de bases trocáveis e a capacidade de troca catiônica diminuíram e a acidez aumentou, indicando tendência do sistema de retornar ao equilíbrio...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Característica química; Bases trocáveis; Carbono orgânico; Frações húmicas; Chemical characteristics; Organic carbon; Humic fractions; Cultivated pasture.; Acidez; Fracionamento; Matéria Orgânica; Nitrogênio; Pastagem Cultivada; Solo.; Acidity; Pantanal; Fractionation; Exchangeable cations; Organic matter; Nitrogen; Soil.
Ano: 2002
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/810747

Chemical changes in argisols under irrigated grape production in the central São Francisco river valley, Brazil
Provedor de dados: Revista Brasileira de Ciência do Solo
Autores: Heck,R. J.; Tiessen,H.; Santos,M. C.; Salcedo,I. H.; Alves,R. J. T.
This study compares the chemical composition of the solution and exchange complex of soil in a 3-year-old irrigated vineyard (Vitis vinifera L., Red Globe cultivar) with that of adjacent clearing in the native hyperxerophyllic 'caatinga' vegetation. The soils are classified as Plinthic Eutrophic Red-Yellow Argisol; according to Soil Taxonomy they are isohyperthermic Plinthustalfs. Detailed physiographic characterization revealed an impermeable gravel and cobble covering the crystalline rocks; the relief of this layer was more undulating than the level surface. Significant higher concentrations of extractable Na, K, Mg and Ca were observed within the vineyard. Lower soil acidity, higher Ca/Mg ratios, as well as lower sodium adsorption and Na/K ratios...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vineyard; Physiography; Moisture content; Exchangeable cations; Electrical conductivity; Soluble cations; Sodicity; Acidity.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832002000100020

Alterations of soil chemical properties by eucalyptus cultivation in five regions in the Rio Doce Valley
Provedor de dados: Revista Brasileira de Ciência do Solo
Autores: Leite,Fernando Palha; Silva,Ivo Ribeiro; Novais,Roberto Ferreira; Barros,Nairam Félix de; Neves,Júlio César Lima.
Little is currently known about modifications in edaphic characteristics caused by short-rotation eucalyptus and the impacts of these alterations on the sustainability of eucalyptus wood production. This study was carried out to identify theses changes at five sites of eucalyptus plantation in the region of the Rio Doce Valley, state of Minas Gerais, Brazil. Areas with more than three previous eucalyptus cycles, adjacent to pasture land or native forest, were chosen. Soil samples were collected and soil fertility analyzed by routine methods and other fractionation methods in order to measure alterations in the K, Ca and Mg contents as a consequence of eucalyptus cultivation. In the eucalyptus areas, reductions in the exchangeable Ca2+, Mg2+ and K+ contents...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Exchangeable cations; Fertilization; Nutrient exhaustion; Nutrient reserves.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000300024

Cation exchange capacity of an oxisol amended with an effluent from domestic sewage treatment
Provedor de dados: Scientia Agricola
Autores: Fonseca,Adriel Ferreira da; Alleoni,Luís Reynaldo Ferracciú; Melfi,Adolpho José; Montes,Célia Regina.
The addition of Na-rich anthropogenic residues to tropical soils has stimulated the scientific community to study the role of sodium in both the soil solution and the exchange complex. In this study, several different methods were used to calculate the concentration of exchangeable and soluble cations and this data was then used to establish correlations between the level of these cations and both the accumulation of various elements and the dry weight of maize grown in a greenhouse under different conditions. In the closed environments of the pots, the most suitable method for calculating the effective cation exchange capacity (ECEC) was the cation exchange capacity calculated by cations removed with barium chloride solution (CEC S). Then again, the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Exchangeable cations; Soil solution; Soil with variable charge; Treated sewage effluent; Maize.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000600007