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Registros recuperados: 7
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Assessment of the soil compaction of two ultisols caused by logging operations Rev. Bras. Ciênc. Solo
Dias Junior,Moacir de Souza; Silva,Sérgio Ricardo; Santos,Nadívio Souza dos; Araujo-Junior,Cezar Francisco.
The impact of wood loads on bulk density and preconsolidation pressure and of harvester and forwarder traffic on rut depth, bulk density and preconsolidation pressure of two Ultisols were examined in this study. Our objective was to quantify the threshold beyond which significant soil compaction and rutting would occur. This study was carried out in the county of Eunápolis, state of Bahia, Brazil, (16 º 23 ' 17 '' S and 39 º 10 ' 06 '' W; altitude 80 m asl) in two Ultisols (PAd2 and PAd3) with different texture classes, in experimental areas with eucalypt plantation. The study involved measurements at the wood load site and machine driving at specific locations in the forest during logging operations. The treatments consisted of one harvester pass and, 8,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Rut depth; Soil compaction; Preconsolidation pressure; Harvest operations.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000600004
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Comparison of estimation methods of soil strength in five soils Rev. Bras. Ciênc. Solo
Ajayi,Ayodele Ebenezer; Dias Junior,Moacir de Souza; Curi,Nilton; Araujo Junior,Cezar Francisco; Aladenola,Olanike Olaiya; Teixeira Souza,Thiago Tadeu; Inda Junior,Alberto Vasconcellos.
In agriculture, the soil strength is used to describe the susceptibility to deformation by pressure caused by agricultural machine. The purpose of this study was to compare different methods for estimating the inherent soil strength and to identify their suitability for the evaluation of load support capacity, compaction susceptibility and root growth. The physical, chemical, mineralogical and intrinsic strength properties of seven soil samples, collected from five sampling pits at different locations in Brazil, were measured. Four clay (CS) and three sandy clay loam (SCL) soils were used. The clay soils were collected on a farm in Santo Ângelo, RS (28 º 16 ' 16 '' S; 54 º 13 ' 11 '' W 290 m); A and B horizons at the Universidade Federal de Lavras, Lavras,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Penetration resistance; Preconsolidation pressure; Load support capacity.
Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000300002
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Compressibility and water availability in Albaqualf soils under different deployment times in no-tillage Scientia Agricola
Reis,Diony Alves; Lima,Cláudia Liane Rodrigues de; Bamberg,Adilson Luís; Ribeiro,Pablo Lacerda.
ABSTRACT: The southern Brazilian lowlands have been historically used for flooded rice cultivation. Over time, heavy machinery and intensive tillage practices have resulted in soil structure disruption, soil compaction, higher production costs and lower agricultural profitability. This study aimed to evaluate the effect of different deployment times of no-tillage (NT). Soil properties including bulk density (BD), compression index (CI), preconsolidation pressure (σp), bulk density at preconsolidation pressure (BDσp), degree of compactness (DC), soil water retention curve (SWRC), plant available water (PAW) and total organic carbon (TOC) content were evaluated using a 30-yr non-cultivated field (NC), adjacent to the experimental plots as a control. The BD,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Lowlands; Preconsolidation pressure; Degree of compactness; Organic carbon.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000500393
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Overpressure within upper continental slope sediments from CPTU data, Gulf of Lion, NW Mediterranean Sea ArchiMer
Lafuerza, S.; Sultan, Nabil; Canals, M.; Frigola, J.; Berne, Serge; Jouet, Gwenael; Galavazi, M.; Sierro, F. J..
Data from in situ piezocone tests (CPTU) and laboratory analyses are utilized for the interpretation of the stress history of Quaternary sedimentary sequences in the upper continental slope of the Gulf of Lion, northwestern Mediterranean Sea. A CPTU based preconsolidation pressure profile referenced to the current effective stress indicates that the deposit is underconsolidated from 12 meters below the seafloor (mbsf) down to at least 150 mbsf. Excess pore pressure below 12 mbsf is further supported by results from oedometer and dissipation tests. Subseafloor pockmarks and indications of free gas in seismic reflection profiles reveal four main overpressure sources (SI-SIV) with overpressure ratios > 0.3 at subseafloor depths coinciding with levels where...
Tipo: Text Palavras-chave: Gulf of Lion; Continental slope; Overpressure; Preconsolidation pressure; Stress history.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6649.pdf
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Soil compaction due to forest harvest operations PAB
Dias Junior,Moacir de Souza; Fonseca,Sebastião da; Araújo Júnior,Cezar Francisco; Silva,Arystides Resende.
The objective of this work was to determine, through the use of the bearing capacity model, the traffic effects of the forest harvest operations on the preconsolidation pressure (sigmap), during one cycle of the eucalyptus plantation. The work was conducted using undisturbed soil samples, collected at the surface of the A horizon and in the top of the B horizon of an Udult (PA), Aquox (FX) and Udox (LA) soils. The undisturbed soil samples were used in the uniaxial compression tests. The soil sampling was done before and after the harvest operations. The operations performed with the Forwarder caused greater soil compaction than the ones done with the Feller Büncher and Harvester. The percentage of soil samples, in the region with additional soil...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Eucalyptus; Soil structure; Preconsolidation pressure; Bearing; Capacity model.
Ano: 2007 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2007000200015
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Soil compaction on traffic lane due to soil tillage and sugarcane mechanical harvesting operations Scientia Agricola
Júnnyor,Wellingthon da Silva Guimarães; Maria,Isabella Clerici De; Araujo-Junior,Cezar Francisco; Lima,Camila Cassante de; Vitti,André César; Figueiredo,Getulio Coutinho; Dechen,Sonia Carmela Falci.
ABSTRACT: Mechanical sugarcane harvesting increases soil compaction due to the intense traffic of agricultural machinery, reducing longevity of sugarcane crops. In order to mitigate the harmful effects caused by agricultural traffic on the soil structure in sugarcane fields, this study evaluated impacts of mechanical sugarcane harvesting on traffic lane under two soil tillage systems based on load bearing capacity models. The experiment was carried out in the region of Piracicaba, state of São Paulo, Brazil, on a Rhodic Nitisol, under conventional tillage (CT) and deep strip-tillage (DST). For CT soil tillage was applied to the entire area with a heavy disk harrow, at operating depths from 0.20 to 0.30 m followed by a leveling harrow at a depth of 0.15 m....
Tipo: Info:eu-repo/semantics/article Palavras-chave: Load bearing capacity; Soil stress distribution; Preconsolidation pressure; Modeling; Environmental sustainability.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001600509
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Structural changes in latosols of the cerrado region: II - soil compressive behavior and modeling of additional compaction Rev. Bras. Ciênc. Solo
Severiano,Eduardo da Costa; Oliveira,Geraldo César de; Dias Júnior,Moacir de Souza; Costa,Katia Aparecida de Pinho; Benites,Vinícius de Melo; Ferreira Filho,Silvio Marcos.
Currently in Brazil, as in other parts of the world, the concern is great with the increase of degraded agricultural soil, which is mostly related to the occurrence of soil compaction. Although soil texture is recognized as a very important component in the soil compressive behaviors, there are few studies that quantify its influence on the structural changes of Latosols in the Brazilian Cerrado region. This study aimed to evaluate structural changes and the compressive behavior of Latosols in Rio Verde, Goiás, through the modeling of additional soil compaction. The study was carried out using five Latosols with very different textures, under different soil compaction levels. Water retention and soil compression curves, and bearing capacity models were...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Preconsolidation pressure; Beneficial pressure; Critical pressure; Degradation of agricultural soils; Particle-size-distribution.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000300014
Registros recuperados: 7
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