|
|
|
Registros recuperados: 17 | |
|
| |
|
|
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: Solo; Característica química; Matéria orgânica; Bases trocáveis; Acidez; Carbono orgânico; Nitrogênio; Fracionamento; Frações húmicas; Pastagem cultivada; Pantanal; Soil; Chemical characteristics; Organic matter; Exchangeable cations; Acidity; Organic carbon; Nitrogen; Fractionation; Humic fractions; Cultivated pasture. |
Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/handle/doc/810747 |
| |
|
|
PICCOLO, M. C.; BIELUCZYK, W.; REIS, L. C.; PEREIRA, M. G.; BALIEIRO, F. C.. |
The identification and quantification of labile and recalcitrant soil organic matter (SOM) forms can be used to evaluate the impacts of management on soil quality (SQ). This study characterized the SOM through chemical and granulometric fractionation in areas located in the Savannah biome. Preserved, cultivated and environmental recovering areas were evaluated. For all fractions of SOM, except for the particulate organic carbon (POC), the preserved areas showed higher levels. The SOM had a positive correlation with the cation exchange capacity and negative with bulk density of soil (p ≤ 0.01). The results showed that SOM improved the physical and chemical SQ, and crops reduced the levels of carbon (C) in SOM fractions, negatively affecting the SQ. |
Tipo: Artigo em anais de congresso (ALICE) |
Palavras-chave: Fracionamento de carbono; Qualidade do solo; Latossolos; Agricultura tropical; Preservação ambiental; Fracionamento; Carbono; Latossolo; Agricultura; Preservação da natureza; Solo; Qualidade; Carbon; Fractionation; Soil quality; Oxisols; Tropical agriculture. |
Ano: 2014 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/1001611 |
| |
|
| |
|
| |
|
|
Grenier, Melanie; Garcia-solsona, Ester; Lemaitre, Nolwenn; Trull, Thomas W.; Bouvier, Vincent; Nonnotte, Philippe; Van Beek, Pieter; Souhaut, Marc; Lacan, Francois; Jeandel, Catherine. |
Distributions of dissolved rare earth element (REE) concentrations and neodymium isotopic compositions (expressed as epsilon(Nd)) of seawater over and off the Kerguelen Plateau in the Southern Ocean are presented. The sampling took place during the austral spring bloom in October-November 2011 (KEOPS2 project, GEOTRACES process study) and aimed to further the investigations of the KEOPS1 austral summer study in terms of sources and transport of lithogenic material, and to investigate the impact of local biogeochemical cycles on the REE distributions. The REE signature of the coastal eastern Kerguelen Islands waters was characterized by negative europium anomalies (Eu/Eu*) and negative epsilon(Nd) in filtered samples. By contrast, the unfiltered sample... |
Tipo: Text |
Palavras-chave: Southern Ocean; Kerguelen Islands; Rare earth elements; Fractionation; Anomalies; Lithogenic; Biologic; GEOTRACES. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00616/72764/72274.pdf |
| |
|
|
Marques,Jean Dalmo de Oliveira; Luizão,Flávio Jesus; Teixeira,Wenceslau Geraldes; Sarrazin,Max; Ferreira,Sávio José Filgueira; Beldini,Troy Patrick; Marques,Elizalane Moura de Araújo. |
Organic matter plays an important role in many soil properties, and for that reason it is necessary to identify management systems which maintain or increase its concentrations. The aim of the present study was to determine the quality and quantity of organic C in different compartments of the soil fraction in different Amazonian ecosystems. The soil organic matter (FSOM) was fractionated and soil C stocks were estimated in primary forest (PF), pasture (P), secondary succession (SS) and an agroforestry system (AFS). Samples were collected at the depths 0-5, 5-10, 10-20, 20-40, 40-60, 60-80, 80-100, 100-160, and 160-200 cm. Densimetric and particle size analysis methods were used for FSOM, obtaining the following fractions: FLF (free light fraction), IALF... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fractionation; Soil organic matter; Land use; Soil physical fractions. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000100232 |
| |
|
|
NACHTIGALL, G.R.; NOGUEIROL, R.C.; ALLEONI, L.R.F.. |
O trabalho teve como objetivo avaliar a distribuição de formas de cobre, em função do pH e da adição de cama-de-frango, em amostras da camada superficial (0 a 10 cm) de um Neossolo Litólico distrófico típico e de um Cambissolo Húmico alumínico típico, da região da Serra Gaúcha, cultivados por mais de 15 anos com parreirais que receberam aplicações sucessivas de produtos fitossanitários à base de cobre. Para avaliar os efeitos da variação do pH e do teor de matéria orgânica do solo nas formas de cobre, cinco doses de HNO3 (50, 100, 200, 300 e 400 mmol kg-1) e quatro doses de cama-de-frango em base seca (10, 20, 40 e 80 t ha-1) foram adicionadas aos solos. As frações observadas foram: trocável; ligada à matéria orgânica; ligada a óxidos de Fe, de Al e de Mn;... |
Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Parreiral; Extração seqüencial; Fracionamento; Matéria orgânica do solo; Vineyards; Sequential extraction; Fractionation; Soil organic matter. |
Ano: 2007 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/124245 |
| |
|
|
FERNANDES, L.A.; FAQUIN, V.; FURTINI NETO, A.E.; CURI, N.. |
Realizou-se um experimento em casa de vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras, com o objetivo de verificar a influência da aplicação de calcário e de P em algumas formas de P em quatro solos de várzea cultivados com feijoeiro. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 x 5 x 2, com quatro repetições, a saber: quatro solos [Glei Húmico (GH), Glei Pouco Húmico (GP), Aluvial (A) e Orgânico (O)], cinco doses de P (75, 150, 300, 500 e 800 mg dm-3 de P) e dois níveis de calagem (sem e com). Os solos foram incubados em vasos, por 30 dias, com as respectivas doses de calcário, e por mais 150 dias, com as doses de P. No final desse período, foram coletadas amostras de solo para... |
Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Phaseolus vulgaris; Adubação fosfatada; Calagem; Fracionamento; Nutrição das plantas; Phosphate fertilizers; Liming; Fractionation; Plant nutrition. |
Ano: 2002 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/106795 |
| |
|
|
Khoshbin khoshnazar,A. R; Jahanshahi,M; Azami,N. S. |
Radiation therapy of the brain is associated with many consequences, including cognitive disorders. Pathogenesis of radiation induced cognitive disorder is not clear, but reduction of neurogenesis in hippocampus may be an underlying reason. 24 adult male rats entered to study. Radiation absorbed dose to midbrain was 10 Gy, delivered by routine cobalt radiotherapy machine which its output was measured 115.24 cGy/min. The rats were divided in four groups of sixes, including groups of control, single fraction 10 Gy, fractionated 10 Gy and finally anaesthesia sham group. Number of pyramidal nerve cells was counted in two regions of hippocampus formation (CA1 and CA3). The radiation could reduce the number of cells in two regions of hippocampus significantly... |
Tipo: Journal article |
Palavras-chave: Hippocampus; Neurogenesis; Radiation; Fractionation. |
Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022012000100026 |
| |
|
|
Baronas, J. Jotautas; Torres, Mark A.; West, A. Joshua; Rouxel, Olivier; Georg, Bastian; Bouchez, Julien; Gaillardet, Jerome; Hammond, Douglas E.. |
Solutes derived from the dissolution of silicate minerals play a key role in Earth’s climate via the carbon and other biogeochemical cycles. Silicon (Si) is a unique constituent of silicate minerals and a biologically important nutrient, so tracing its behavior in near-surface environments may provide important insights into weathering processes. However, Si released by weathering is variably incorporated into secondary mineral phases and biota, obscuring signals derived from primary weathering processes. Due to chemical similarities, Germanium (Ge) may help better understand the Si cycle and its relationship to chemical weathering. With this aim, we report new measurements of the concentration and isotopic composition of Ge for both the dissolved and... |
Tipo: Text |
Palavras-chave: Germanium; Silicon; Isotopes; Rivers; Weathering; Fractionation. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00460/57196/59370.pdf |
| |
|
|
Zhang, Congmu; Xie, Kun; Chen, Ming-Hsun; Rosentrater, Kurt R.. |
The objective of this project was to separate distillers dried grains with solubles (DDGS) into high protein and high fiber fractions, in order to improve value and utility as a livestock feed. This project used a laboratory-scale cylindrical blower (Iowa blower) and a laboratory-scale gravity table (Whippet V-80 separator, Sutton, Steele & Steele, Inc.). The raw DDGS was sieved into multiple streams using 10 mesh, 20 mesh and 40 mesh screens. The 10-20 mesh fraction and 20-40 mesh fraction were then run on the blower and the separator separately, using the same settings for air velocity in the range of 0.32 m/sec to 3.06 m/sec. A high protein fraction was achieved (37.13% db) for the 10-20 mesh fraction with an air velocity of 2.42 m/sec by the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Processing DDGS; Fractionation; Air classification; Gravity table; Protein; Fiber. |
Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3141 |
| |
|
| |
|
|
Lima,Ronaldo Lima de; Enke,Dariane Beatriz Schoffen; Braun,Neiva; Fracalossi,Débora Machado. |
Fish meal is widely included in animal feed because it contains ideal essential amino acids profile, it is rich in energy, essential fatty acids, vitamins and minerals and with >80% apparent protein digestibility in peneid shrimp. In human nutrition, studies are investigating the inclusion of fish meal in snacks, cakes, breads and cookies, as an enrichment in calcium, phosphorus, iron, protein and, especially, omega-3 fatty acids. Omega-3 fatty acids reduces heart diseases and have antithrombotic and anti-inflammatory properties (eicosapentaenoic acid), and are essential to the formation of brain tissue and retina in infants and are important during pregnancy and lactation (docosahexaenoic acid). Fish meal produced from fish waste is rich in minerals... |
Tipo: Info:eu-repo/semantics/report |
Palavras-chave: Phosphorus; Fish waste meal; Fractionation; Sieves.. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782014001001841 |
| |
|
|
OLIVEIRA, M.F.G.; NOVAIS, R.F.; NEVES, J.C.L.; VASCONCELLOS, C.A.; ALVES, V. M. C.. |
Para determinar o zinco "disponivel" do solo para plantas, varios procedimentos de extracao tem sido desenvolvidos. Uma alternativa utilizada no estudo de extratores do Zn "disponivel" refere-se ao fracionamento do Zn total de solo, com vistas em entender suas reacoes no solo e o comportamento dos extratores. Este trabalho objetivou avaliar a dependencia existente entre o teor de Zn disponivel, por diferentes extratores, e as fracoes deste elemento no solo e caracteristicas dos solos. Para isto, amostras de doze solos da camada de 0-20 cm de profundidade, correspondendo aos grandes grupos de Latossolo Vermelho-Escuro (LE), Latossolo Vermelho-Amarelo (LV), Latossolo Amarelo (LA), Podzolico Vermelho-Amarelo (PV) e Areia Quartzosa (AQ), receberam as doses de... |
Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Zinco; Fracionamento; Micronutrientes; Solo; Analise; Zinc; Fractionation; Micronutrient; Soil; Analysis. |
Ano: 1999 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/483394 |
| |
|
|
Rangel,Carlos M. A.; Baptista Neto,José A.; Fonseca,Estefan M.; McAlister,John; Smith,Bernard J.. |
In this study, the geochemical analysis of ten sediment samples collected along the fluvial system of the Estrela River, which flows into the northern portion of Guanabara Bay, shows the presence of anthropogenic impacts in this area. Concentrations of Fe, Mn, Zn, Cu, Pb, Cr and Ni obtained were slightly higher, when compared with values found innatural environments. The particle size and organic matter content in most of the analyzed stations showed featuresnot conducive to the accumulation of pollutants due to the low organic matter content and the strong presence ofsand fraction. There was also the fractionation of heavy metals in sediments and it was found the prominence ofresidual and reducible phase, besides the significant occurrence of organic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Estrela River; Guanabara Bay; Heavy metal; Fractionation. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300005 |
| |
|
| |
Registros recuperados: 17 | |
|
|
|