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| Registros recuperados: 17 | |
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| Junior,Daniel Dias Valadão; Biachini,Aloísio; Valadão,Franciele Caroline Assis; Rosa,Rodrigo Pengo. |
| This study aimed to evaluate the effect of penetration rate and the size of the cone base on the resistance to penetration under different soil moistures and soil bulk density. The experimental design was completely randomized in a 4x2x2x2 factorial arrangement, with the factors, soil bulk density of 1.0; 1.2; 1.4 and 1.6 Mg m-3, soil moisture at the evaluation of 0.16 and 0.22 kg kg-1, penetration rates of 0.166 and 30 mm s-1 and areas of the cone base of 10.98 and 129.28 mm² resulting in 32 treatments with 8 replicates. To ensure greater uniformity and similarity to field conditions, samples passed through cycles of wetting and drying. Only the interaction of the four factors was not significant. Resistance values varied with the density of the soil,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil bulk density; Soil moisture; Methodology. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052014000200012 |
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| Souza,Igor Alexandre de; Ribeiro,Karina Guimarães; Rocha,Wellington Willian; Pereira,Odilon Gomes; Cecon,Paulo Roberto. |
| The physical properties and fertility of the soil are important factors in the formation and establishment of pasture. Changes in physical properties affect the movement of water, air, nutrients and roots, which, in turn, affect the productivity and longevity of pastures. The objective of this study was to evaluate the physical properties of the soil and the dry matter yield of a pasture with signalgrass cv. Basilisk (Brachiaria decumbens cv. Basilisk), fertilized with increasing nitrogen doses (N), on a dystrophic Red-Yellow Latosol. The experiment was conducted on the Fazenda Rio Manso of the Universidade Federal dos Vales do Jequitinhonha e Mucuri, in Couto de Magalhães de Minas, State of Minas Gerais, Brazil. To evaluate the annual forage yield, a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pre-consolidation pressure; Soil bulk density; Total pore volume; Void index. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600011 |
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| Machado,Walquíria; Telles,Tiago Santos; Tavares Filho,João; Guimarães,Maria de Fátima; Alves,Grace Bungenstab; Borges,José Luiz Bernardo. |
| This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Saccharum officinarum; Soil bulk density; Porosity; Soil penetration resistance; Soil aggregate stability. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000600004 |
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| Macedo,Sônia de Fátima Schilickmann; Grimaldi,Michel; Medina,Cristiane Conti; Cunha,José Edézio da; Guimarães,Maria de Fátima; Tavares Filho,João. |
| ABSTRACT Soil structure plays an important role in water retention, infiltration capacity, porosity, and penetration resistance. The aim of this study was to evaluate the unsaturated hydraulic conductivity and physical properties of Oxisol soils (bulk density and macro-, micro-, and total porosity) in the structures identified using the profil cultural method in areas under two different management practices (perennial pasture and sugarcane). Three pits were dug in each plot to find out how homogeneous morphological structural units (HMSU) were organized in the soil. Next, unsaturated hydraulic conductivity (Ki) was measured in situ inside each HMSU using a triple-ring infiltrometer at multiple suction. Six samples were collected (two samples for each kind... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil use; Compaction; Soil bulk density; Soil porosity. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100524 |
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| Pires,Luiz F.; Reichardt,Klaus; Cooper,Miguel; Cássaro,Fabio A.M.; Dias,Nivea M.P.; Bacchi,Osny O.S.. |
| Soil pore structure characterization using 2-D image analysis constitutes a simple method to obtain essential information related to soil porosity and pore size distribution (PSD). Such information is important to infer on soil quality, which is related to soil structure and transport processes inside the soil. Most of the time soils are submitted to wetting and drying cycles (W-D), which can cause important changes in soils with damaged structures. This report uses 2-D image analysis to evaluate possible modifications induced by W-D cycles on the structure of damaged soil samples. Samples of three tropical soils (Geric Ferralsol, GF; Eutric Nitosol, EN; and Rhodic Ferralsol, RF) were submitted to three treatments: 0WD, the control treatment in which... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil bulk density; Soil water content; Soil porosity; Micromorphology; Soil structure; Compaction. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000100016 |
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| Gubiani,Paulo Ivonir; Jong Van Lier,Quirijn de; Reichert,José Miguel; Goulart,Rafael Ziani; Fontanela,Eracilda. |
| ABSTRACT: During linear deformation (h) in a soil sample, the variation of the void ratio with respect to deformation (dε/dh) and the respective variation of soil bulk density (dρ/dh) are identical only for a specific value of h. Consequently, if two compression curves are drawn for the same soil sample, one using ρ and the other using ε, there are differences in both the calculated precompression stress (σp) and compression index (Ic). In this study, we highlight the causes by a mathematical analysis and an experimental investigation, quantifying the differences in σp and Ic when using ε and ρ. σp and Ic were calculated for 103 compression curves of an ultisol and 193 of an oxisol. The σp (kPa) using ρ (σpρ) was greater than when using ε (σpε), and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Void ratio; Particle density; Soil bulk density. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000100076 |
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| Neves,Carmen Silvia Vieira Janeiro; Murata,Ives Massanori; Stenzel,Neusa Maria Colauto; Medina,Cristiane de Conti; Borges,Andrey Vetorelli; Okumoto,Sergio Hideki; Lee,Roberto Huo Chian; Kanai,Hernandes Takeshi. |
| Field studies on citrus roots are important for genetic selection of cultivars and for management practices such as localized irrigation and fertilization. To characterize root systems of six rootstocks, taking into consideration chemical and physical characteristics of a clayey Typic Hapludox of the Northern State of Paraná, this study was performed having as scion the 'IAC-5 Tahiti' lime [Citrus latifolia (Yu. Tanaka)]. The rootstocks 'Rangpur' lime (C. limonia Osbeck), 'Africa Rough' lemon (C. jambhiri Lush.), 'Sunki' mandarin [C. sunki (Hayata) hort. ex Tan.], Poncirus trifoliata (L.) Raf., 'C13' citrange [C. sinensis (L.) Osb. x P. trifoliata (L.) Raf] and 'Catânia 2' Volkamer lemon (C. volkameriana Ten. & Pasq.) were used applying the trench... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Citrus latifolia; Root system; Trench profile method; Soil bulk density. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000100016 |
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| Mazurana,Michael; Levien,Renato; Müller,Jônatan; Conte,Osmar. |
| The introduction and intensification of no-tillage systems in Brazilian agriculture in recent decades have created a new scenario, increasing concerns about soil physical properties. The objective of this study was to assess the effects of different tillage systems on some physical properties of an Ultisol previously under native grassland. Five tillage methods were tested: no-tillage (NT), chiseling (Ch), no-tillage with chiseling every two years (NTCh2), chiseling using an equipment with a clod-breaking roller (ChR) and chiseling followed by disking (ChD). The bulk density, macroporosity, microporosity and total porosity, mechanical resistance to penetration, water infiltration into the soil and crop yields were evaluated. The values of soil bulk... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil bulk density; Soil resistance to penetration; Soil porosity. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000400013 |
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| Registros recuperados: 17 | |
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