Reference soil Colombia 05: Alisol

CO005

Alisols occur in the tropics and subtropics, and in the warm temperate regions of the world in relatively young landscapes. The high level of exchangeable aluminium in these soils is caused by rapid weathering of secondary high-activity clays such as vermiculite and smectite.

Characteristics

Soils having an argic horizon (a subsurface horizon with distinct higher clay content than the overlying horizon), which has a cation exchange capacity of 24 cmolc per kg clay or more, and which starts either within 100 cm from the soil surface, or within 200 cm from the soil surface if the argic horizon is overlain by loamy sand or coarser textures throughout. They have "alic" properties (high content of exchangeable aluminium) in the major part between 25 and 100 cm from the soil surface; moreover, only such diagnostic horizons as an ochric, albic, andic, ferric, nitic, plinthic, or vertic horizon are present.

Distribution of Alisols (rough estimation supplied by soilgrids)

 

Reference soil CO005: Alisols

PARENT MATERIAL: Mainly fluviatile, non-consolidated sediments. VEGETATION AND LAND USE: The tropical rainforest (bosque humedo tropical) was cleared 5 years previously; presently a grass, herb and shrub cover; grazing; in some cleared forest foddercrops are grown ADDITIONAL NOTES ON PROFILE DESCRIPTION: BC2 - mixture of colours: 2.5YR6/6, 10R4/8, 7.5YR6/8 and 10YR7/4; 150-250cm - as BC2, but material becomes sandier below 200 cm. within 150 cm presence of plinthite is observed. According to PRORADAM the soil belongs to unit PMa, low level,old alluvial terrace soils; compare profile CO006, oxic Dystropept

 

Classification

WRB 2006WRB 1998
Albic-Cutanic- Alisol (Alumic Humic Clayic)Cutani-Albic- Luvisol (Hyperdystric)
100-150 cmplinthic horizon
10-30 cmalbic horizon
10-75 cmargic horizon
0-30 cmochric horizon
10-30 cmalbic horizon
10-75 cmargic horizon
-strongly humic
FAO-UNESCO-ISRIC 1988FAO-UNESCO-ISRIC 1974
Alumi-Plinthic AlisolPlinthic Acrisol
0-30 cmochric A horizon
10-30 cmalbic E horizon
10-75 cmargic B horizon
- cmargic B horizon
- cmochric A horizon
-plinthite
0-30 cmochric A horizon
10-30 cmalbic E horizon
10-75 cmargillic B horizon
-plinthite