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Registros recuperados: 23 | |
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FILIZOLA, H. F.; FONTANA, A.; DONAGEMMA, G. K.; SOUZA, M. D. de; BORTOLON, E. S. O.; BORTOLON, L.. |
Resumo: As terras onde predominam solos arenosos distribuem-se em extensas áreas em todas as regiões do Brasil, sendo muito utilizadas em áreas de intensificação da agricultura. O uso desses solos nos sistemas agrícolas tem efeito sobre suas características e atributos. Com o objetivo de avaliar as consequências desse uso sobre algumas das suas propriedades físicas foi selecionada uma área localizada em uma propriedade agrícola no município de Guaraí (TO). Em amostras de solos coletadas em 18 trincheiras foram avaliadas a textura, a estabilidade dos agregados, o grau de floculação das argilas, a porosidade, a densidade, a condutividade hidráulica saturada (K s ), a infiltração e a retenção da água no solo. Os solos avaliados não apresentam nenhum dos... |
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Solo arenoso; Física do solo; Uso da terra; Textura do solo; Condutividade hidráulica; Porosidade; Retenção de água no solo; Sandy soils; Soil physical properties; Aggregate stability; Soil texture; Soil density; Hydraulic conductivity; Soil water retention; Soil permeability. |
Ano: 2017 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1081400 |
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FILIZOLA, H. F.; FONTANA, A.; DONAGEMMA, G. K.; SOUZA, M. D. de; BORTOLON, E. S. O.; BORTOLON, L.. |
Resumo: As terras onde predominam solos arenosos distribuem-se em extensas áreas em todas as regiões do Brasil, sendo muito utilizadas em áreas de intensificação da agricultura. O uso desses solos nos sistemas agrícolas tem efeito sobre suas características e atributos. Com o objetivo de avaliar as consequências desse uso sobre algumas das suas propriedades físicas foi selecionada uma área localizada em uma propriedade agrícola no município de Guaraí (TO). Em amostras de solos coletadas em 18 trincheiras foram avaliadas a textura, a estabilidade dos agregados, o grau de floculação das argilas, a porosidade, a densidade, a condutividade hidráulica saturada (K s ), a infiltração e a retenção da água no solo. Os solos avaliados não apresentam nenhum dos... |
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Solo arenoso; Física do solo; Uso da terra; Textura do solo; Condutividade hidráulica; Porosidade; Retenção de água no solo; Sandy soils; Soil physical properties; Aggregate stability; Soil texture; Soil density; Hydraulic conductivity; Soil water retention; Soil permeability. |
Ano: 2017 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1075224 |
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PINTO, J. M.; SOARES, J. M.. |
Este trabalho correspondeu a avaliacao do aspersor DANTAS modelo MD-20A com bocais, 3,1 mm x 2,5mm e 5,6 mm x 2,5mm, com as pressoes de 2, 3, 4 e 5 atm, conduzido no Campo Experimental de Bebedouro, Petrolina, PE. Foi determinada a uniformidade de distribuicao; o coeficiente de uniformidade de Christiansen e a eficiencia de irrigacao. A avaliacao da uniformidade do aspersor envolveu tambem a construcao de isoietas. Determinou-se a rotacao do aspersor, a velocidade e a direcao do vento predominante. Constatou-se que o aspersor modelo MD-20A com bocais 3,1mm x 2,5mm deve ser manejado satisfatoriamente com pressao de 3 atm no espacamento de 12m x 18m com pressao de servico de 5 atm. A rotacao minima (3 rpm) obtida com esse modelo de aspersores, com bocais de... |
Tipo: Capítulo em livro técnico (INFOTECA-E) |
Palavras-chave: Irrigação; Aspersão; Aspersor; Condutividade Hidráulica; Irrigation; Hydraulic conductivity; Sprinkler irrigation. |
Ano: 1989 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/132864 |
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Jansen, S.; Gortan, E.; Lens, F.; Assunta Lo Gullo, M.; Salleo, S.; Scholtz, A.; Stein, A.; Trifilò, P.; Nardini, A.. |
• The hydraulic conductance of angiosperm xylem has been suggested to vary with changes in sap solute concentrations because of intervessel pit properties. • The magnitude of the ‘ionic effect’ was linked with vessel and pit dimensions in 20 angiosperm species covering 13 families including six Lauraceae species. • A positive correlation was found between ionic effect and vessel grouping parameters, especially the portion of vessel walls in contact with neighbouring vessels. Species with intervessel contact fraction (FC) values < 0.1 showed an ionic effect between 2% and 17%, while species with FC values > 0.1 exhibited a response between 10% and 32%. The ionic effect increased linearly with the mean fraction of the total vessel wall area occupied... |
Tipo: Article / Letter to the editor |
Palavras-chave: Angiosperms; Hydraulic conductivity; Intervessel pit membrane; Ionic effect; Vessel grouping; Wood anatomy; 42.41. |
Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/423644 |
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Lens, F.; Sperry, J.S.; Christmas, M.A.; Rabaey, D.; Jansen, S.. |
• Vulnerability to cavitation and conductive efficiency depend on xylem anatomy. We tested a large range of structure–function hypotheses, some for the first time, within a single genus to minimize phylogenetic ‘noise’ and maximize detection of functionally relevant variation. • This integrative study combined in-depth anatomical observations using light, scanning and transmission electron microscopy of seven Acer taxa, and compared these observations with empirical measures of xylem hydraulics. • Our results reveal a 2 MPa range in species’ mean cavitation pressure (MCP). MCP was strongly correlated with intervessel pit structure (membrane thickness and porosity, chamber depth), weakly correlated with pit number per vessel, and not related to pit area... |
Tipo: Article / Letter to the editor |
Palavras-chave: Acer; Cavitation resistance; Hydraulic conductivity; Pit structure; Rare pit hypothesis; Vessel distribution; Vessel wall thickenings; Wood density; 42.56. |
Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/429474 |
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Soracco,Carlos Germán; Lozano,Luis Alberto; Villarreal,Rafael; Palancar,Telmo Cecilio; Collazo,Daniel Jorajuria; Sarli,Guillermo Oliveiro; Filgueira,Roberto Raúl. |
Soil compaction has been recognized as a severe problem in mechanized agriculture and has an influence on many soil properties and processes. Yet, there are few studies on the long-term effects of soil compaction, and the development of soil compaction has been shown through a limited number of soil parameters. The objectives of this study were to evaluate the persistence of soil compaction effects (three traffic treatments: T0, without traffic; T3, three tractor passes; and T5, five tractor passes) on pore system configuration, through static and dynamic determinations; and to determine changes in soil pore orientation due to soil compaction through measurement of hydraulic conductivity of saturated soil in samples taken vertically and horizontally.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Effective porosity; Total porosity; Soil pore anisotropy; Hydraulic conductivity. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000200408 |
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Soracco,Carlos Germán; Lozano,Luis Alberto; Villarreal,Rafael; Melani,Esteban; Sarli,Guillermo Oliverio. |
ABSTRACT: Determination of soil physical quality (SPQ) is very important because it is related to many important soil processes. However, it is not clear which indicators should be considered in this evaluation, and information about temporal variation of SPQ under different soil tillage systems is scarce. The aim of this study was to determine the effects of no tillage (NT) and conventional tillage (CT) on temporal variation of capacity SPQ indicators [bulk density (BD), macroporosity (Pmac), air capacity (AC), plant available water capacity (PAWC), relative field capacity (RFC), Dexter's (S), and structural stability index (SSI)], and dynamic SPQ indicators [field saturated hydraulic conductivity (K0), water-conducting macroporosity (εma), and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hydraulic conductivity; Soil water retention curve; Pore continuity index. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100410 |
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Silva,Monica Martins da; Libardi,Paulo Leonel; Fernandes,Flávia Carvalho Silva. |
Determining the intensity of the water balance components in the control volume of a soil, and consequently defining the most likely periods of occurrence of a water deficit in a crop, is an exercise that requires knowledge about soil, climate and plant factors. This research aimed to evaluate soil water balance components at phenological stages of corn (Zea mays L.) under no-till system, when fertilized with 60, 120, and 180 kg ha-1 of nitrogen. The field experiment was carried out in Piracicaba, State of São Paulo, Brazil, on a Typic Hapludox. Evaluations were made in the 2004/2005 and 2005/2006 corn cropping seasons, divided over three stages according to the plant's phenology. Runoff was not taken into account. Measurements were made for precipitation... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Internal drainage; Hydraulic conductivity; Actual evapotranspiration; Tensiometer; No-till system. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000400013 |
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Villagra,M. M.; Michiels,P.; Hartmann,R.; Bacchi,O.O.S.; Reichardt,K.. |
Experimentally determined values of unsaturated soil hydraulic conductivity are presented for an Alfisol of the county of Piracicaba, S.P., Brazil. Simultaneous measurements of soil water content and pressure head are made along a 125 m transect within an irrigated field during the internal drainage process. Calculations of the soil hydraulic conductivity were made using the instantaneous profile method (Watson, 1966) and the unit gradient method (LIBARDI et al., 1980). The spatial variability of the soil hydraulic conductivity manifested along the transect indicates the need to develop a field method to measure K(theta) within prescribed fiducial limits, taking into account quantitative evaluation of spatial and temporal variances associated with the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil variability; Hydraulic conductivity. |
Ano: 1994 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161994000100018 |
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Chavarriaga Montoya,William; Cruz Cerón,Gabriel; Cuervo Correa,Johan. |
Abstract The mass movement of soils, are soil, rocks displacements or both, caused by soil water excesses in terrains due to gravity effects and other factors. The aim of this research was to quantify the moisture retention capacity of volcanic soils as a threat indicator in the mass removal phenomena. This research was carried out on soils of the Malteria - Las Margaritas road transept to Magdalena river, right bank of the Chinchiná river in the Department of Caldas, Colombia. Through soil sample design, 3 altitudinal ranges were stratified as follows: high, medium and low. In fact, representative plant cover was taken in the study area, sampling the combination of the following variables: "plant cover" and "altitudinal range". In total, 52 points were... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hydraulic conductivity; Humidity threat; Soil aggregates; Soil mass removal; Stability. |
Ano: 2017 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122017000400588 |
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Bermúdez-Florez,Leidy Natalia; Cartagena-Valenzuela,José Régulo; Ramírez-Builes,Víctor Hugo. |
Abstract Coffee cultivation depends on water supplied by rain or irrigation, which, in turn, affect productivity and harvest distribution. Knowing the influence of plant spacing on the behavior of soil moisture and water consumption, is likely to determine a crop’s planting density, fertilization and planting times, all based on regional water availability. In this context, the study was conducted at Naranjal Experimental Station, municipality of Chinchiná (Caldas, Colombia) at 04° 58’ N, 75° 39’ W; 1,381 m a.s.l., aimed to describe moisture performance in a coffee plantation established on an Andisol, under three planting densities. This was done by estimating the evapotranspiration (ETo) and assessing crop evapotranspiration (ETc). Soil moisture was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Plant spacing; Andisol; Soil moisture; Hydraulic conductivity. |
Ano: 2018 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122018000300402 |
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Mahmood-ul-Hassan, Muhammad; National Agricultural Research Centre; rafique, Eajaz; National Agricultural Research Centre; Rashid, Abdul; National Agricultural Research Centre. |
A 5-year cotton–wheat rotation field experiment was conducted on two alkaline-calcareous soils to investigate the impact of integrated nutrient-management and crop-residue incorporation on soil physical and hydrological properties. The nutrient treatments were: T1–farmers' fertilizer use; T2–balanced nutrient management (recommended N, P, Zn. and B from mineral sources); T3–integrated nutrient management, same as T2, except that 75% N was applied from fertilizer and 25% as FYM; and T4 same as T2, except that every alternate year, wheat was substituted by Berseem green manure. All treatments were compared with and without crop residue incorporation. Soil organic matter (SOM) content in both the soils was significantly increased with T2, T3 and T4 as... |
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Palavras-chave: Cotton-wheat system; Crop-residue recycling; Integrated nutrient management; Bulk density; Water stable aggregate; Hydraulic conductivity. |
Ano: 2012 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/14683 |
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Domingues, Rafael; Pereira, André Belmont; Pires, Luiz Fernando; Schiebelbein, Luis Miguel; Barbosa, Eduardo Augusto Agnellos; Auler, André Carlos. |
Beans crop is an agricultural staple largely consumed in Brazil because it is part of the basic food of the population. Such a crop is usually grown by small growers and turns out to be of a great social and economical importance. The aim of the current manuscript was to scrutinize the effect of soil water status on its physical attributes, such as bulk density, total porosity, macroporosity, microporosity, hydraulic conductivity under protected environment conditions on beans crop (Phaseolus vulgaris L.). The effect of the soil physical attributes on the biological response of the plants was also investigated. The experiment was installed in March of 2016 in a greenhouse. The experimental design was completely randomized in a factorial scheme with four... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agronomy; Agrometeorology; Soil Physics; Irrigation Science Phaseolus vulgaris L; Hydraulic conductivity; Soil moisture; Macroporosity; Microporosity; Bulk density. |
Ano: 2018 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4585 |
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Registros recuperados: 23 | |
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