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| Almeida,Jaime Antonio de; Cararo,Denis Cesar; Uberti,Antônio Ayrton Auzani. |
| Dark subsurface horizons, with properties similar to the sombric horizon characterized by the USA Soil Taxonomy, are frequent in Southern Brazil. The genesis of this horizon is controversial and poorly understood. This study aimed to describe the occurrence of sombric-like horizons in Ultisols in the South of Santa Catarina State, at low altitudes, and suggest possible processes of humus transference, accumulation and persistence in these horizons. Physical, chemical and mineralogical properties of four Ultisols were evaluated; three were sampled in a toposequence, and another representative one in an isolated profile (RSP). The dark subsurface horizons coincide with the AB and BA transitional genetic horizons; they are acid, low in base saturation, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dark subsurface horizon; Podzolization; Buried A horizon; Clay-humic substances; Climatic changes. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000200018 |
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| Gomes,João Bosco Vasconcellos; Araújo Filho,José Coelho; Vidal-Torrado,Pablo; Cooper,Miguel; Silva,Elen Alvarenga da; Curi,Nilton. |
| ABSTRACT Horizons with varying degrees of cementation are a common feature of the soils from the coastal tablelands of Northeastern Brazil. In most cases, these horizons are represented by the following subsurface horizons: fragipan, duripan, ortstein, and placic. The aims of this study were to analyze differences regarding the development and the degree of expression of cementation in soils from the coastal tablelands of Northeastern Brazil: Planossolo Háplico (p-SX), Espodossolo Humilúvico (p-EK), Espodossolo Ferrihumilúvico (p-ESK), and Argissolo Acinzentado (p-PAC) pedons. The pedons studied displayed features related to drainage impediments. The cemented horizons from p-SX and p-EK had the same designation (Btgm), displaying a duric character that... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fragipan; Duric character; Podzolization. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100302 |
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| Toma,Maíra Akemi; Owens,Phillip Ray; Silva,Carlos Alberto; Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Curi,Nilton. |
| In soil surveys, it is usual to find profiles with an uncommon disposition of horizons. Dark horizons in depth might be either the consequence of erosion and redeposition of soil materials from upslope or an indication of the podzolization process, which forms a spodic horizon. Few laboratory analyses are known to characterize dark subsurface horizons which could allow for the differentiation of spodic from buried A horizons. Some researchers propose C-humic and C-fulvic acid fraction ratios and forms of carbon to analyze characteristics of these horizons. Therefore, this research aimed to characterize dark subsurface horizons found in soils under a Eucalyptus minimum tillage system in the state of Rio Grande do Sul, Brazil, and to relate soil organic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Humic substances; Organic matter; Erosion; Podzolization; Redeposition. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000400334 |
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| Silva,Elen Alvarenga; Gomes,João Bosco Vasconcellos; Araújo Filho,José Coelho de; Vidal-Torrado,Pablo; Cooper,Miguel; Curi,Nilton. |
| The scarcity of comprehensive characterizations of soils associated to gentle summit depressions of the Northeastern Brazilian Coastal Plains justifies this work, which had as objective to provide basic information for the more diverse agricultural and non-agricultural uses. For that, representative soils (Spodosols or similar soils) from these environments were selected in Alagoas, Sergipe and Bahia states. This approach included characterization of morphological, mineralogical and micromorphological properties of the soil profiles, employing standard procedures. The morphological characterization corroborated the effect of the podzolization process during the formation of these soils. The mineralogy of the clay fraction of these soils was basically... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sand-quartzous soils; Cementation; Hydromorphism; Podzolization; Barreiras Formation. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542012000500003 |
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