Reference soil groups (WRB)
From Wicri Urban Soils
| World Reference Base for soil resources |
|---|
Contents
- 1 The Reference soil groups
- 1.1 Soils with thick organic layers
- 1.2 Soils with strong human influence
- 1.3 Soils with limited rooting due to shallow permafrost or stoniness
- 1.4 Soils influenced by water
- 1.5 Soils set by Fe/Al chemistry
- 1.6 Soils with stagnating water
- 1.7 Accumulation of organic matter, high base status
- 1.8 Accumulation of less soluble salts or non-saline substances
- 1.9 Soils with a clay-enriched subsoil
- 1.10 Relatively young soils or soils with little or no profile development
- 2 See also
The Reference soil groups
The 32 reference soil groups can be sorted in 10 categories :
Soils with thick organic layers
Soils with strong human influence
- Anthrosols, soils with long and intensive agricultural use
- Technosols, soils containing many artefacts
Soils with limited rooting due to shallow permafrost or stoniness
Soils influenced by water
- Vertisols, with alternating wet-dry conditions, rich in swelling clayss
- Fluvisols, floodplains, tidal marshes
- Solonetz, alkaline soils
- Solonchaks, with salt enrichment upon evaporation
- Gleysols, groundwater affected soils
Soils set by Fe/Al chemistry
- Andosols : with allophanes or Al-humus complexes
- Podzols : with cheluviation and chilluviation
- Plinthosols : with an accumulation of Fe under hydromorphic conditions
- Nitisols : with low-activity clay, P fixation, strongly structured
- Ferralsols : dominance of kaolinite and sesquioxides
Soils with stagnating water
- Planosols, with abrupt textural discontinuity
- Stagnosols, with structural or moderate textural discontinuity
Accumulation of organic matter, high base status
- Chernozems : typically mollic
- Kastanozems : transition to drier climate
- Phaeozems : transition to more humid climate
Accumulation of less soluble salts or non-saline substances
Soils with a clay-enriched subsoil
- Albeluvisols, with albeluvic tonguing
- Alisols : with a low base status, high-activity clay
- Acrisols : with a low base status, low-activity clay
- Luvisols : with a high base status, high-activity clay
- Lixisols : with a high base status, low-activity clay
Relatively young soils or soils with little or no profile development
- Umbrisols, with an acidic dark topsoil
- Arenosols, sandy soils
- Cambisols, moderately developed soils
- Regosols, soils with no significant profile development
See also
- The FAO reference text, (2007 version)
- The classification key of the WRB
