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Registros recuperados: 46 | |
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Martins,Paula Cristina Caruana; Dias Junior,Moacir de Souza; Andrade,Maria Luiza de Carvalho; Guimarães,Paulo Tácito Gontijo. |
The main source of soil structure degradation in coffee plantation is the machinery traffic because these operations may cause soil compaction affecting the crop development. This study aimed to generate the load-bearing capacity models for a Red-Yellow Latosol and to determine through the use of these models the soil susceptibility to compaction of the coffee plantation due to the implantation time and the compaction caused by the machinery traffic on the traffic lines located at the top and bottom of the ground. This study was carried out in the EPAMIG Experimental Farm, located at Três Pontas, MG, in coffee plantations (Coffee arabica L.) with 2, 7, 18 and 33 years of establishment. To obtain the load-bearing capacity models, 12 undisturbed soil samples... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precompression stress; Structure degradation; Soil physics. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542012000400002 |
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Schlindwein,Jairo André; Miotti,Alan Antonio; Fioreli-Perira,Elaine Cosma; Pequeno,Petrus Luiz de Luna; Bortolon,Leandro; Marcolan,Alaerto Luiz. |
Soil clay content is an important soil attribute and has been used to classification of phosphorus status in the soil in order to determinate the needing of phosphorus amounts to be applied to crops production. The aim of this research was to adjust the method for soil clay content determination, adopted by the laboratories of Southern Brazil (ROLAS-RS/SC), for soil clay content evaluation in Rondônia soils. The study was conducted using 50 soil samples from Rondônia State with wide range clay content. It was tested shaking periods (1.5, 2.0 and 2.5h) associated with periods for soil particles decantation (1.5 and 2.0h) to correlate with the standard method for soil texture testing, known as the pipette method. Clay content determined through this method... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clay determination; Clay decantation; Shaking period; Soil texture; Soil physics. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782011001200010 |
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Moraes,Moacir T. de; Silva,Vanderlei R. da; Zwirtes,Anderson L.; Carlesso,Reimar. |
Soil physical quality can be easily and quickly evaluated by using simple equipment to identify levels of soil compaction. Hence, it is necessary to know the variables responsible for changes in the soil penetration resistance (SPR). The aim of this review is to identify the main factors related to the various equipment used for assessing SPR as a soil physical quality indicator in agriculture. This literature review describes the different types of equipment used and its relationship with SPR. A wide range of procedures, devices, and equipments are available. Much of variability in SPR results is related to the equipment model, cone angle and diameter, and penetration rate. Usually, restrictions to root growth are correlated with SPR values above 2-3 MPa.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil compaction; Soil physics; Physical quality; Penetrometry. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000100019 |
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Tavanti,Renan F. R.; Freddi,Onã da S.; Tavanti,Tauan R.; Rigotti,Adriel; Magalhães,Wellington de A.. |
ABSTRACT The least limiting water range (LLWR) is a soil physical quality indicator that receives much attention. It has been criticized and put to the test regarding mathematical models that compose it since they describe the behavior of soil physical attributes in a simplified way. This study aimed to assess the efficiency of some pedofunctions proposed in the literature and artificial neural networks on the accuracy in predicting soil water retention at potentials equivalent to field capacity (θFC) and permanent wilting point (θPWP). In other words, to apply the best models to LLWR of two soil types (Oxisol and Ultisol) and verify changes in their structure. The results indicated that pedofunctions using sand, silt, clay, bulk density, and soil organic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil physics; Soil physical quality indicator; Available water; Pedotransfer functions; Artificial neural networks. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000400444 |
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Analises fisicas; Preparo da amostra; Terra fina, cascalho e calhaus;Umidade atual; Umidade residual e fator "f"; Umidade obtida no aparelho extrator de Richards; Umidade obtida com a mesa de tensao; Densidade aparente; Porosidade total; Microporosidade (Metodo Mesa de Tensao); Macroporosidade; Analise granulometrica (Dispersao Total); Argila dispersa em agua; Grau de floculacao; Relacao silte/argila; Condutividade hidraulica; Percentagem de saturacao; Percentagem de agregados; Limite de liquidez; Limite e indice de plasticidade; Limite de pegajosidade; Limite de contracao (LC) (Metodo do Mercurio Metalico); Grau de contracao (GC); Superficie especifica (Metodo Simplificado); Separacao de argila e silte para analises de raios X; Coeficiente de... |
Tipo: Livros |
Palavras-chave: Solo; Física do solo; Química do solo; Análise do solo; Mineralogia; Soil chemistry; Soil analysis; Mineralogy; Soil; Soil physics. |
Ano: 1997 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/330804 |
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PEQUENO, P. L. de L.; LEONIDAS, F. das C.; MENDES, A. M.; VIEIRA, A. H.; MARTINS, E. P.; VASCONCELOS, L. P. de. |
O recurso natural solo pode ser definido como um corpo natural, sintetizado em forma de perfil, composto de uma mistura variável de minerais, divididos em pedaços e desintegrados e de matéria orgânica em decomposição, que cobre a terra em uma camada fina e que fornece, quando contém, as quantidades necessárias de ar e de água, amparo mecânico e em parte, subsistência para os vegetais. De uma maneira geral, os solos minerais apresentam quatro componentes principais: substâncias minerais (45%), matéria orgânica (5%), água (25%) e ar (25%). Encontrado-se, sobretudo, num estado realmente adiantado de subdivisão e intimamente misturados. Dentre as propriedades físicas do solo, a textura e a estrutura são de grande importância. A textura diz respeito ao tamanho... |
Tipo: Folhetos |
Palavras-chave: Água; Física do Solo; Umidade do Solo; Soil physics; Soil water. |
Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/703805 |
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Registros recuperados: 46 | |
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