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| Moraes,Moacir T. de; Debiasi,Henrique; Franchini,Julio C.; Silva,Vanderlei R. da. |
| Soil compaction caused by machinery traffic reduces crop yields. This study aimed to evaluate the effects of intensive traffic, and the soil water content, on the soil penetration resistance (PR) of a Rhodic Eutrudox (Distroferric Red Latosol, Brazilian Classification), managed under no-tillage (NT). The experiment consisted of six treatments: NT with recent chiseling, NT without additional compaction, and NT with additional compaction by 4, 8, 10 and 20 passes of a harvester with a weight of 100 kN (70 kN on the front axle). Undisturbed soil samples were collected at 5.5-10.5 cm and 13.5-18.5 cm depth to quantify the soil bulk density (BD). The PR was assessed in four periods, using an impact penetrometer, inserted in the soil to a depth of 46 cm. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil layers with mechanical impedance; No-tillage; Soil compaction; Soil consistency; Soil profile. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000400014 |
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| Rodrigues,Cristiane; Oliveira,Virlei Álvaro de; Silveira,Pedro Marques da; Santos,Glenio Guimarães. |
| Knowledge of the soil physical properties, including the clay content, is of utmost importance for agriculture. The behavior of apparently similar soils can differ in intrinsic characteristics determined by different formation processes and nature of the parent material. The purpose of this study was to assess the efficacy of separate or combined pre-treatments, dispersion methods and chemical dispersant agents to determine clay in some soil classes, selected according to their mineralogy. Two Brazilian Oxisols, two Alfisols and one Mollisol with contrasting mineralogy were selected. Different treatments were applied: chemical substances as dispersants (lithium hydroxide, sodium hydroxide, and hexametaphosphate); pre-treatment with dithionite, ammonium... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemical agents; Soil classes; Diagnostic horizon; Analysis methodology; Soil particles; Soil profile. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000500013 |
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| Becerra,Alejandra; Bartoloni,Norberto; Cofré,Noelia; Soteras,Florencia; Cabello,Marta. |
| Arbuscular mycorrhizal fungi (AMF) colonize land plants in every ecosystem, even extreme conditions such as saline soils. In the present work we report for the first time the mycorrhizal status and the vertical fungal distribution of AMF spores present in the rhizospheric soil samples of four species of Chenopodiaceae (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana and Suaeda divaricata) at five different depths in two saline of central Argentina. Roots showed medium, low or no colonization (0-50%). Nineteen morphologically distinctive AMF species were recovered. The number of AMF spores ranged between 3 and 1162 per 100 g dry soil, and AMF spore number decreased as depth increased at both sites. The highest spore number was recorded... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Arbuscular mycorrhiza; Saline environments; Soil profile; Vertical distribution; Mycorrhizal status. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000200029 |
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