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| Registros recuperados: 47 | |
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| Júnnyor,Wellingthon da Silva Guimarães; Severiano,Eduardo da Costa; Silva,Alessandro Guerra da; Gonçalves,Wainer Gomes; Andrade,Renata; Martins,Brendow Roberto Rodrigues; Custódio,Guilherme Dias. |
| ABSTRACT Increasing attention has recently been given to sweet sorghum as a renewable raw material for ethanol production, mainly because its cultivation can be fully mechanized. However, the intensive use of agricultural machinery causes soil structural degradation, especially when performed under inadequate conditions of soil moisture. The aims of this study were to evaluate the physical quality of aLatossolo Vermelho Distroférrico (Oxisol) under compaction and its components on sweet sorghum yield forsecond cropsowing in the Brazilian Cerrado (Brazilian tropical savanna). The experiment was conducted in a randomized block design, in a split plot arrangement, with four replications. Five levels of soil compaction were tested from the passing of a tractor... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sorghum bicolor (L.); Sowing time; Soil structure; Water limitation; Least limiting water range; Agroenergy. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000601744 |
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| Beldini,Troy Patrick; McNabb,Kenneth L; Lockaby,B. Graeme; Sanchez,Felipe G; Navegantes-Câncio,Osvaldo; Oliveira,Raimundo Cosme de. |
| Eucalyptus grandis and other clonal plantations cover about 3.5 million ha in Brazil. The impacts of intensively-managed short-rotation forestry on soil aggregate structure and Carbon (C) dynamics are largely undocumented in tropical ecosystems. Long-term sustainability of these systems is probably in part linked to maintenance of soil organic matter and good soil structure and aggregation, especially in areas with low-fertility soils. This study investigated soil aggregate dynamics on a clay soil and a sandy soil, each with a Eucalyptus plantation and an adjacent primary forest. Silvicultural management did not reduce total C stocks, and did not change soil bulk density. Aggregates of the managed soils did not decrease in mass as hypothesized, which... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Jari; Soil structure; Subsoiling; Sustainability. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000600008 |
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| Caviglione,João H.. |
| ABSTRACT From the 1990s, the demand for soil quality indicators has increased with the agricultural sustainability approaches. The S-index was proposed as an indicator of soil physical quality. The objective was to evaluate the sensitivity of S-index as an indicator of soil physical quality and its correlation with bulk density, organic carbon content, macroporosity, microporosity, total porosity and clay, sand and silt contents, under field conditions in the diversity of the Paraná state. Samples were collected from 21 sites with textures from clay and heavy clay, in the layers of 0-0.1 and 0.1-0.2 m, in soil under native forest and in cultivated soil. Eight soil physical attributes were determined. A soil-water retention curve with six moisture points... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil-water retention curve; Soil structure; Soil porosity; Van Genuchten-Mualem. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000700458 |
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| Gennaro,Lorena Adriana De; Souza,Zigomar Menezes de; Weill,Mara de Andrade Marinho; Souza,Gustavo Soares de; Alves,Marlene Cristina. |
| Agricultural management systems can alter the physical and biological soil quality, interfering with crop development. The objective of this study was to evaluate the physical and microbiological attributes of a Red Latosol, and its relationship to the biometric parameters of the common bean (Phaseolus vulgaris), irrigated and grown under two management systems (conventional tillage and direct seeding), in Campinas in the state of São Paulo, Brazil. The experimental design was of randomised blocks, with a split-plot arrangement for the management system and soil depth, analysed during the 2006/7 and 2007/8 harvest seasons, with 4 replications. The soil physical and microbiological attributes were evaluated at depths of 0.00-0.05, 0.05-0.10, 0.10-0.20 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil structure; Soil organic matter; Soil microbial activity; Direct seeding; Phaseolus vulgaris. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000400002 |
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| Dec,Dorota; Dorner,José; Becker-Fazekas,Orsolya; Horn,Rainer. |
| In order to determine the effect of bulk density and soil structure on their hydraulic behaviour, undisturbed samples were collected and disturbed samples were prepared from a Luvisol. The experimental field, located in Harste/Goettingen, Germany, was cultivated with sugar beet (Beta vulgaris). The water retention curve (WRC) and saturated hydraulic conductivity (Ks) were measured on undisturbed samples and homogenized samples prepared at different bulk densities (1.2 -1.4 and 1.6 Mg m-3). To determine the effect of soil shrinkage on the unsaturated hydraulic conductivity (k/Ψ) ,the vertical deformation of the repacked samples was measured and relative water content differences (dθ)were determined. The hydraulic properties of soils with... |
| Tipo: Journal article |
Palavras-chave: Water retention curve; Soil shrinkage; Soil structure. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912008000100001 |
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| Razafimbelo,Tantely; Chevallier,Tiphaine; Albrecht,Alain; Chapuis-Lardy,Lydie; Rakotondrasolo,Fela Nirina; Michellon,Roger; Rabeharisoa,Lilia; Bernoux,Martial. |
| Soil organic carbon (SOC) is usually said to be well correlated with soil texture and soil aggregation. These relations generally suggest a physical and physicochemical protection of SOC within soil aggregates and on soil fine particles, respectively. Because there are few experimental evidences of these relations on tropical soils, we tested the relations of soil variables (SOC and soil aggregate contents, and soil texture) with the amount of SOC physically protected in aggregates on a set of 15 Malagasy soils. The soil texture, the SOC and water stable macroaggregate (MA) contents and the amount of SOC physically protected inside aggregates, calculated as the difference of C mineralized by crushed and intact aggregates, were characterized. The relation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Macroaggregate; Tropical soils; Soil structure; Carbon stabilization. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000300009 |
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| Cooper,Miguel; Boschi,Raquel Stucchi; Silva,Vitor Boschi da; Silva,Laura Fernanda Simões da. |
| ABSTRACT Studies of soil porosity through image analysis are important to an understanding of how the soil functions. However, the lack of a simplified methodology for the quantification of the shape, number, and size of soil pores has limited the use of information extracted from images. The present work proposes a software program for the quantification and characterization of soil porosity from data derived from 2-D images. The user-friendly software was developed in C++ and allows for the classification of pores in terms of size, shape, and combinations of size and shape. Using raw data generated by image analysis systems, the software calculates the following parameters for the characterization of soil porosity: total area of pore (Tap), number of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil structure; Soil thin sections; Soil porosity data; Pore morphology. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000400388 |
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| Lima,Cláudia Liane Rodrigues de; Dupont,Patrícia Bianca; Pillon,Clenio Nailto; Miola,Ezequiel Cesar Carvalho. |
| ABSTRACT: Agricultural areas in the region of Turuçu, on the Southeast Hillside in the state of Rio Grande do Sul (RS), Brazil present many examples of soil physical degradation. Accordingly, strategies aimed at evaluating and ameliorating the structural quality of soils should be developed to ensure the sustainable use of these areas. This study aimed to evaluate the least limiting water range (LLWR), S-index, compressibility parameters, organic carbon and the organic matter granulometric fractions of a Udalf under different agricultural uses. Soil samples with disturbed and non-disturbed structure from the 0.00 to 0.10 m layer were collected on farms in the Southeast Hillside, Turuçu region, RS, for analyzing soil under: i) conventional system of corn... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil quality; Soil physics; Soil structure; Soil compaction. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000100100 |
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| Pértile,Patricia; Holthusen,Dörthe; Gubiani,Paulo Ivonir; Reichert,José Miguel. |
| ABSTRACT: The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was to use the amplitude sweep test, a rheometry technique, to investigate the microstructural strength of four subtropical soils (two Oxisols, an Ultisol and a Vertisol) and to discuss difficulties with respect to the samples, water content, soil density and vertical force. The various rheological properties which reveal the soil microstructural strength were determined: deformation at the end of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil mechanics; Oscillatory shear; Amplitude sweep test; Soil structure. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000200154 |
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| Guimarães,Rachel Muylaert Locks; Tormena,Cássio Antonio; Alves,Sérgio José; Fidalski,Jonez; Blainski,Éverton. |
| The crop-livestock system can promote soil compaction in surface layers, mainly due to animal trampling. However, plants and their root growth, in interaction with animal trampling, can decrease the deleterious changes in soil structure caused by this system. Up to the present time, the physical soil modifications in crop-livestock systems, including oat and ryegrass crops for winter animal forages are unknown. The objective of this study was to quantify and to relate tensile strength, friability and soil organic carbon in an Oxisol under a crop-livestock system. The study was conducted in Campo Mourão - Paraná, Brazil. Four forage heights were used for the winter forages: 7, 14, 21 and 28 cm. For each forage height, five soil blocks were randomly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aggregate; Soil structure; No-tillage; Soil physical quality; Microstructure. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000400011 |
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| Ćirić,Vladimir; Manojlović,Maja; Belić,Milivoj; Nešić,Ljiljana; Šeremešić,Srdan. |
| Aggregate stability is an important factor of the soil functioning. Greater aggregate stability leads to greater soil organic carbon (SOC) preservation, while SOC acts as a key cementing agent in aggregation processes. The objective of this study was to investigate the effects of native vegetation conversion in soil aggregate stability and SOC concentration. The investigation was conducted in the Vojvodina Province, Serbia, in July 2009. Undisturbed soil samples were taken from Haplic Chernozem, Haplic Fluvisol and Gleyic Vertisol, at a depth ranging from 0 to 20 cm. A completely randomized experimental design was used with three replicates. Each soil type was considered under treatments 1) cropland >100 years, 2) native meadow and 3) native... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aggregate stability; Soil organic carbon; Land use change; Soil type; Soil structure. |
| Ano: 2013 |
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952013000600002 |
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| Registros recuperados: 47 | |
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