|
|
|
|
|
| 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 |
| |
|
|
| Almeida,Jaime Antonio de; Lunardi Neto,Antônio; Vidal-Torrado,Pablo. |
| The sombric horizon is a diagnostic subsurface horizon defined in the soil classification system of the United States (Soil Taxonomy) and FAO (WRB), used to classify the soil at different categorical levels. The sombric horizon has a soil color darker than the overlying surface(s) horizon(s), and must show illuvial humus accumulation features, though they are not associated with aluminum (Al), as in the spodic horizon, nor associated with sodium (Na), as in the natric horizon. There are also criteria to distinguish it from buried A horizons. However, since the first references and proposed concept of the sombric horizon in African soils made by Sys and co-workers in the 1960s, and adopted by the Soil Taxonomy edition of 1975, few modifications have been... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Subsurface horizon; Illuvial humus accumulation; Buried A horizon; Soil classification; SiBCS. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000100087 |
| |
|
|
|
