Consulta: subjectFacets:"Humic fractions"
Registros recuperados: 4
Data/hora: 12/06/2024 14:00:52

Alterações na matéria orgânica e nas características químicas de um Podzol hidromórfico sob pastagens cultivadas no Pantanal Sul-Mato-Grossense.
Provedor de dados: 14
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

Soil organic matter as affected by management systems, phosphate fertilization, and cover crops
Provedor de dados: 86
Autores: Souza,Géssica Pereira de; Figueiredo,Cícero Célio de; Sousa,Djalma Martinhão Gomes de.
Abstract The objective of this work was to evaluate the effects of soil management systems, cover crops, and phosphate fertilization on soil humic fractions in a long-term experiment. The treatments consisted of conventional tillage and no-tillage with pearl millet (Pennisetum glaucum) or velvet bean (Mucuna aterrima) as cover crops, at two doses of phosphorous: 0 and 100 kg ha-1 P2O5 per year. Soil samples were taken 11 years after the establishment of the experiment and analyzed for soil total organic carbon and carbon content of humic fractions at 0.00-0.05, 0.05-0.10, and 0.10-0.20-m depths. The humic fractions are sensitive to soil management, except free fulvic acid, which was the only one that did not reduce its carbon contents on the surface layer...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Humic fractions; No-tillage; Organic matter fractions; Phosphate fertilization; Soil fertility; Soil quality.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901668

Effect of management systems and cover crops on organic matter dynamics of soil under vegetables
Provedor de dados: 90
Autores: Souza,Rodrigo Fernandes de; Figueiredo,Cícero Célio de; Madeira,Nuno Rodrigo; Alcântara,Flávia Aparecida de.
Vegetable production in conservation tillage has increased in Brazil, with positive effects on the soil quality. Since management systems alter the quantity and quality of organic matter, this study evaluated the influence of different management systems and cover crops on the organic matter dynamics of a dystrophic Red Latosol under vegetables. The treatments consisted of the combination of three soil tillage systems: no-tillage (NT), reduced tillage (RT) and conventional tillage (CT) and of two cover crops: maize monoculture and maize-mucuna intercrop. Vegetables were grown in the winter and the cover crops in the summer for straw production. The experiment was arranged in a randomized block design with four replications. Soil samples were collected...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Organic carbon; Oxidizable fractions; Microbial biomass; Humic fractions.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000300024

Organic Matter Fractions and Quality of the Surface Layer of a Constructed and Vegetated Soil After Coal Mining. I - Humic Substances and Chemical Characterization
Provedor de dados: 90
Autores: Leal,Otávio dos Anjos; Castilhos,Rosa Maria Vargas; Pauletto,Eloy Antonio; Pinto,Luiz Fernando Spinelli; Fernandes,Flávia Fontana; Penning,Letiane Helwig; Rosa,Carla Machado da.
After open coal mining, soils are “constructed”, which usually contain low levels and quality of organic matter (OM). Therefore, the use of plant species for revegetation and reclamation of degraded areas is essential. This study evaluated the distribution of carbon (C) in the chemical fractions as well as the chemical characteristics and humification degree of OM in a soil constructed after coal mining under cultivation of perennial grasses. The experiment was established in 2003 with the following treatments: Hemarthria altissima (T1), Paspalum notatum (T2), Cynodon dactilon (T3), Urochloa brizantha (T4), bare constructed soil (T5), and natural soil (T6). In 2009, soil samples were collected from the 0.00-0.03 m layer and the total organic carbon stock...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Humic fractions; Infrared; Laser-induced fluorescence; Perennial grasses.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000300886