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| Registros recuperados: 45 | |
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| Murillo de la Rosa, Arnulfo. |
| Los suelos de la sabana de Huimanguillo, se localizan en lomeríos con pendientes ligeras, son de baja fertilidad, presentan alta acidez con pH que oscilan entre 4.0 a 5.5 y contenidos de materia orgánica de 1 a 4 %, a veces hasta de 20 %. La materia orgánica desempeña un papel importante en el suelo ya que aporta una gran variedad de elementos nutritivos para las plantas, y modifica la estructura del mismo, el conocimiento sobre su aporte de nutrientes es escaso, por lo que, las estimaciones del suministro al suelo se basan más bien en el rendimiento. El presente trabajo tuvo como objetivo estimar la densidad aparente (Dap), las reservas de carbono orgánico total (COT), nitrógeno total (Nt), la relación carbono nitrógeno (C/N), el carbono orgánico soluble... |
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Palavras-chave: Acrisol; Agroecosistemas; Densidad aparente; Carbono orgánico total; Nitrógeno total; Carbono orgánico soluble; Indice óptico y relación C/N; Agroecosystems; Bulk density; Total organic carbon; Total nitrogen; Soluble organic carbon; Optical index and C/N; Maestría; Producción Agroalimentaria en el Trópico. |
| Ano: 2010 |
URL: http://hdl.handle.net/10521/254 |
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| Lahr,Francisco A. R.; Nogueira,Marta C. de J. A.; Araujo,Victor A. De; Vasconcelos,Juliano S.; Christoforo,André L.. |
| ABSTRACT Over the years, the species of eucalyptus has become a multipurpose raw material. In addition, the most relevant aspect of the use for various purposes is related to the production of a high quality wood, coming from short duration plantations, which is fundamental to the current demand of the industries. However, its use in civil construction has not yet reached a level of importance, due to the low knowledge of many of its resistance properties and the consequent popular fear in the use of reforestation woods, in particular the Eucalyptus grandis. This research investigated its main mechanical properties, aiming to reinforce its constructive applications in wood structures. For this, two physical properties and fourteen mechanical properties, in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rose Gum; Eucalypt; Mechanical properties; Bulk density. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000500642 |
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| Goneli,André L. D.; Corrêa,Paulo C.; Figueiredo Neto,Acácio; Kirsch,Michele R. H.; Botelho,Fernando M.. |
| ABSTRACT Knowledge regarding the static pressure drop in granular layers is of fundamental importance in the development of efficient drying and aeration projects of agricultural products. Thus, the objective of this study was to evaluate the effects of impurity contents on the static pressure drop in different bed depth of castor bean grains, as well as modify the mathematical models per the obtained experimental data and select the model that best represents this phenomenon. First, impurities in castor bean grains of the Guarani variety were eliminated and 6% of the moisture content (dry basis) was retained. The coarse impurity contents were obtained with 2%, 4%, and 6% of mass addition. The pressure drop in different bed depth of clean and impure castor... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bulk density; Load loss; Porosity; Ricinus communis L.; Moisture content. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200184 |
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| SANTOS,DIEGO DOS; SOUZA,EDUARDO G. DE; NÓBREGA,LÚCIA H. P.; BAZZI,CLAUDIO L.; QUEIROZ,FERNANDO N. DE. |
| Cover crops are important for improving soil quality. However, soil properties usually have some spatial dependence. Thus, this study aimed to evaluate the effect of winter cover crops on physical properties of soil and soybean yields using thematic maps. Five winter treatments were used: black oats; intercropping 1 (forage turnips and black oats); intercropping 2 (forage turnips, black oats and common vetch); wheat; and control. Macroporosity, microporosity, total porosity, bulk density and water content of the soil from 0 - 0.1 m depths were evaluated after the winter cover crop management. Soybeans were sown over the entire area in the summer after the winter cover crop management, and the soybean yield was determined for each treatment. Maps for each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil porosity; Bulk density; Crop rotation. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162015000200280 |
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| Carvalho,Laércio A. de; Meurer,Ismael; Silva Junior,Carlos A. da; Centurion,José F.. |
| The aim of this study was to characterize the spatial variability of soil bulk density (Bd), soil moisture content (θ) and total porosity (Tp) in two management systems of sugarcane harvesting, with or without burning, in a Haplustox soil, in the 0-0.20 m layer. The study area is located in Rio Brilhante, state of Mato Grosso do Sul, Brazil, in Eldorado Sugar Mill. The plots have presented 180 m length, and 145.6 m width, totaling 90 points distributed in the form of a grid of nine rows by ten columns, with points spaced 20 m from its neighbor. Soil samples were collected at 0-0.20 m layer in 2007/2008 and 2008/2009 crops. The harvest with burning system had a higher density compared to mechanized harvest, in the two study periods. The moisture content as... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mechanized harvesting; Bulk density; Saccharum spp. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000100007 |
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| Seben Junior,Getulio de Freitas; Corá,José Eduardo; Lal,Rattan. |
| Soils of the tropics are prone to a decrease in quality after conversion from native forest (FO) to a conventional tillage system (CT). However, the adoption of no-tillage (NT) and complex crop rotations may improve soil structural quality. Thus, the aim of this study was to evaluate the physical properties of an Oxisol under FO, CT, and three summer crop sequences in NT: continuous corn (NTcc), continuous soybean (NTcs), and a soybean/corn rotation (NTscr). Both NT and CT decreased soil organic carbon (SOC) content, SOC stock, water stable aggregates (WSA), geometric mean diameter (GMD), soil total porosity (TP), macroporosity (MA), and the least limiting water range (LLWR). However they increased soil bulk density (BD) and tensile strength (TS) of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: No-tillage; Soil organic carbon; Soil aggregate; Bulk density; Tropical soil; Cerrado. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400021 |
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| Martins,Paula Cristina Caruana; Dias Junior,Moacir de Souza; Ajayi,Ayodele Ebenezer; Moreira,Fátima Maria de Souza. |
| Incongruous management techniques have been associated with some significant loss of agricultural land to degradation in many parts of the world. Land degradation results in the alteration of physical, chemical and biological properties of the soil, thereby posing a serious threat to sustainable agricultural development. In this study, our objective is to evaluate the changes in a Cambisol structure under six land use systems using the load bearing capacity model. Sampling was conducted in Amazonas Region, Brazil, in the following land use: a) young secondary forest; b) old secondary forest; c) forest; d) pasture; e) cropping, and f) agroforestry. To obtain the load bearing capacity models the undisturbed soil samples were collected in those land use... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Structure degradation; Bulk density; Precompression stress; Amazonas. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000600006 |
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| Seben Junior,Getulio de Freitas; Corá,José Eduardo; Lal,Rattan. |
| The no-till system with complex cropping sequences may improve the structural quality and carbon (C) sequestration in soils of the tropics. Thus, the objective of this study was to evaluate the effects of cropping sequences after eight years under the no-till system on the physical properties and C sequestration in an Oxisol in the municipality of Jaboticabal, Sao Paulo, Brazil. A randomized split-block design with three replications was used. The treatments were combinations of three summer cropping sequences - corn/corn (Zea mays L.) (CC), soybean/soybean (Glycine max L. Merryll) (SS), and soybean-corn (SC); and seven winter crops - corn, sunflower (Helianthus annuus L.), oilseed radish (Raphanus sativus L.), pearl millet (Pennisetum americanum (L.)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Crop rotation; Winter crops; Soil aggregates; Least limiting water range; Bulk density. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400023 |
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| Veiga,Milton da; Reinert,Dalvan José; Reichert,José Miguel; Kaiser,Douglas Rodrigo. |
| Soil tillage promotes changes in soil structure. The magnitude of the changes varies with the nature of the soil, tillage system and soil water content and decreases over time after tillage. The objective of this study was to evaluate short-term (one year period) and long-term (nine year period) effects of soil tillage and nutrient sources on some physical properties of a very clayey Hapludox. Five tillage systems were evaluated: no-till (NT), chisel plow + one secondary disking (CP), primary + two (secondary) diskings (CT), CT with burning of crop residues (CTb), and CT with removal of crop residues from the field (CTr), in combination with five nutrient sources: control without nutrient application (C); mineral fertilizers, according to technical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bulk density; Pore size distribution; Manure. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000400008 |
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| Maria,Isabella Clerici De; Chiba,Márcio Koiti; Costa,Alan; Berton,Ronaldo Severiano. |
| Water resource quality is a concern of today's society and, as a consequence, low pollutant wastewaters and sludges are being increasingly treated, resulting in continuous production of sewage sludge. Sewage sludge (SS) can be used as soil physical conditioner of agricultural or degraded lands, due to its organic C component. The objective of this research was to evaluate the long-term SS effects on soil physical quality of properties such as bulk density, porosity, permeability and water retention of degraded soils treated with annual SS applications. The SS rates were calculated according to the crop N demand. The field experiment consisted of three treatments: mineral fertilization, 10 and 20 Mg ha-1 of SS (once and twice the SS quantity to meet the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil quality; Bulk density; Soil permeability. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000300038 |
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| Islabão,Gláucia Oliveira; Lima,Cláudia Liane Rodrigues de; Vahl,Ledemar Carlos; Timm,Luis Carlos; Teixeira,Juliana Brito da Silva. |
| ABSTRACT The combustion of rice husk generates a partially burnt mixture called rice husk ash (RHA) that can be used as a source of nutrients to crops and as a conditioner of soil physical properties. The objective of this study was to evaluate the effect of RHA levels on the hydro-physical properties of a Typic Hapludult. The experimental design was composed of random blocks with four replications, which comprised plots of 24 m2 and treatments with increasing RHA rates: 0, 40, 80 and 120 Mg ha-1. Undisturbed soil samples were collected in the soil layers of 0.00-0.10 and 0.10-0.20 m after nine months of RHA application, using steel cylinders (0.03 m of height and 0.047 m of diameter). These samples were used to determine soil bulk density (Bd), total soil... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bulk density; Soil porosity; Available water capacity; Soil compressibility; Soil aggregation. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100407 |
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| Tuchtenhagen,Ivana Kruger; Lima,Cláudia Liane Rodrigues de; Bamberg,Adilson Luís; Guimarães,Rachel Muylaert Locks; Mansonia,Pulido-Moncada. |
| ABSTRACT The “Visual Evaluation of Soil Structure” (VESS) is a method used primarily to evaluate the soil structural quality of Oxisols in Brazil and secondly for more specific research, consultancy, and teaching purposes. Since the methodology was never applied and compared with laboratory evaluations of physical properties of hydromorphic soils of the Pampa biome in the south of Brazil, this study evaluated the use of VESS as a visual indicator of the structure quality of a typic eutrophic Albaqualf soil under native grassland, crop-livestock integration, no-tillage, and conventional management systems. Experimental areas with these different management systems were subjected to visual (VESS) and laboratory evaluation of the soil structure. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil degradation; Bulk density; Tensile strength; No-tillage; Conventional tillage. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100412 |
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| Martins,Elton A. S.; Goneli,André L. D.; Hartmann Filho,Cesar P.; Mauad,Munir; Siqueira,Valdiney C.; Gonçalves,Alexandre A.. |
| ABSTRACT Safflower is an oil crop and its oil can be used for food and industrial purposes. However, there is little information about the physical properties of these grains, which is important for the planning and execution of post-harvest stages. Thus, this study was carried out with the aim of evaluating the effect of drying on the main physical properties of safflower grains. Safflower grains were harvested with an initial moisture content of approximately 0.445 decimal d.b. (dry basis) and subjected to drying in an oven with forced air circulation at 40 °C, until the grains reached a final moisture content of 0.073 ± 0.008 decimal d.b. During the drying, bulk density and true density, porosity, thousand-grain mass, circularity, sphericity, projected... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carthamus tinctorius L.; Bulk density; Shape of grains. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000500344 |
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| VEIGA,MILTON DA; DAMBRÓS,REMI NATALIN; DALBÓ,MARCO ANTÔNIO. |
| RESUMO Os atributos do solo estão relacionados com o desenvolvimento e a produção das culturas, tanto anuais como perenes. O presente trabalho teve como objetivo determinar os atributos químicos e físicos do solo três anos após a aplicação de sistemas de manejo para implantação de porta-enxertos de videira, em um Nitossolo Vermelho com textura muito argilosa. Os sistemas de manejo consistiram na confecção ou não de camalhões e/ou de drenos antes da implantação das mudas de porta-enxertos Dog Ridge. Os atributos químicos (pH em água e teores de matéria orgânica e de macronutrientes) foram determinados em amostras coletadas na linha da cultura, nas camadas de 0-0,1; 0,1-0,2; 0,2-0,3 e 0,3-0,4 m de profundidade. Os atributos físicos do solo (teor de argila,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: PH; Organic matter; Macronutrients; Bulk density; Porosity; Penetration resistance; Vitis. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452015000300797 |
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| Pariz,Cristiano Magalhães; Carvalho,Morel de Passos e; Chioderoli,Carlos Alessandro; Nakayama,Fernando Takayuki; Andreotti,Marcelo; Montanari,Rafael. |
| The objective of this study was to analyze variability, linear and spatial correlations of forage dry mass yield (FDM) and dry matter percentage (DM%) of Brachiaria decumbens with the bulk density (BD), gravimetric (GM) and volumetric (VM) moisture, mechanical resistance to penetration (RP) and organic matter content (OM), at depths 1 (0-0.10 m) and 2 (0.10-0.20 m), in a Red Latosol (Oxisol), in order to select an indicator of soil physical quality and identify possible causes of pasture degradation. The geostatistical grid was installed to collect soil and plant data, with 121 sampling points, over an area of 2.56 ha. The linear correlation between FDM × DM% and FDM × BD2 was low, but highly significant. Spatial correlations varied inversely and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bulk density; Geostatistics; Gravimetric and volumetric moisture; Mechanical resistance to penetration; Organic matter. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011001000007 |
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| Veiga,Milton da; Balbinot Junior,Alvadi Antonio; Oliveira,Daniela Aparecida de. |
| The sowing of winter pastures in areas used for summer grain production and their management under direct cattle grazing can cause changes in soil physical attributes, whose intensity depends on the degree of soil mobilization, grazing interval, stocking rate and weather. To study these aspects it was conducted over four years an experiment in a randomized block with split plots design and four replications. In the main plots were applied two forms of sowing the annual winter pasture (direct seeding and seeding + harrowing) and, in the subplots, four intervals between grazing (7, 14 and 28 days and ungrazed). Undisturbed soil cores were sampled at the end of each grazing cycle, in the 0-0.05 m layer to determine the saturated hydraulic conductivity and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crop-livestock integration system; Bulk density; Porosity; Saturated hydraulic conductivity; Aggregate stability. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000500005 |
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| Registros recuperados: 45 | |
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