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WRB Reference Soil Groups - Markdown

The WRB Reference Soil Groups represent the highest hierarchical level in the World Reference Base for Soil Resources (WRB), established by the International Union of Soil Sciences (IUSS). The fourth edition of 2022 defines 32 Reference Soil Groups (RSGs), systematically classified based on soil-forming processes and characteristics. This classification system is widely used as a standard reference for creating soil maps and facilitating international soil information exchange.

soil classification WRB IUSS Reference Soil Groups soil science pedology

| code | slug | name | description | category |
| --- | --- | --- | --- | --- |
| HS | histosol | Histosol | Soils with thick organic layers. | Soils with thick organic layers |
| AT | anthrosol | Anthrosol | Soils with long and intensive agricultural use, often altered to enhance fertility. | Soils with strong human influence |
| TC | technosol | Technosol | Soils containing significant amounts of artefacts. | Soils with strong human influence |
| CR | cryosol | Cryosol | Permafrost-affected soils. | Soils with limitations to root growth |
| LP | leptosol | Leptosol | Thin soils or soils with many coarse fragments. | Soils with limitations to root growth |
| SN | solonetz | Solonetz | Soils with a clay-enriched subsoil with high concentrations of exchangeable Na. | Soils with limitations to root growth |
| VR | vertisol | Vertisol | Soils with high contents of shrink-swell clays, alternating wet-dry conditions. | Soils with limitations to root growth |
| SC | solonchak | Solonchak | Soils with high concentrations of soluble salts. | Soils with limitations to root growth |
| GL | gleysol | Gleysol | Groundwater-dominated soils, underwater or in tidal areas. | Soils distinguished by Fe/Al chemistry |
| AN | andosol | Andosol | Soils with allophanes and/or complexes of Al and organic matter. | Soils distinguished by Fe/Al chemistry |
| PZ | podzol | Podzol | Soils with subsoil accumulation of organic matter and/or oxides. | Soils distinguished by Fe/Al chemistry |
| PT | plinthosol | Plinthosol | Soils with accumulation and redistribution of Fe. | Soils distinguished by Fe/Al chemistry |
| PL | planosol | Planosol | Soils with stagnant water and abrupt textural difference. | Soils distinguished by Fe/Al chemistry |
| ST | stagnosol | Stagnosol | Soils with stagnant water and no or only moderate textural difference. | Soils distinguished by Fe/Al chemistry |
| NT | nitisol | Nitisol | Soils with low-activity clays, P fixation, many Fe oxides, strongly structured. | Soils distinguished by Fe/Al chemistry |
| FR | ferralsol | Ferralsol | Soils with dominance of kaolinite and oxides. | Soils distinguished by Fe/Al chemistry |
| CH | chernozem | Chernozem | Soils with very dark and well-structured topsoil and secondary carbonates. | Pronounced accumulation of organic matter in the mineral topsoil |
| KS | kastanozem | Kastanozem | Soils with dark topsoil and secondary carbonates. | Pronounced accumulation of organic matter in the mineral topsoil |
| PH | phaeozem | Phaeozem | Soils with dark topsoil, no secondary carbonates (unless very deep), and high base status. | Pronounced accumulation of organic matter in the mineral topsoil |
| UM | umbrisol | Umbrisol | Soils with dark topsoil and low base status. | Pronounced accumulation of organic matter in the mineral topsoil |
| DU | durisol | Durisol | Soils with accumulation of, and cementation by, secondary silica. | Accumulation of moderately soluble salts or non-saline substances |
| GY | gypsisol | Gypsisol | Soils with accumulation of secondary gypsum. | Accumulation of moderately soluble salts or non-saline substances |
| CL | calcisol | Calcisol | Soils with accumulation of secondary carbonates. | Accumulation of moderately soluble salts or non-saline substances |
| RT | retisol | Retisol | Soils with interfingering of coarser-textured, lighter-coloured material into a finer-textured, stronger-coloured layer. | Soils with clay-enriched subsoil |
| AC | acrisol | Acrisol | Soils with low-activity clays and exchangeable Al greater than exchangeable base cations. | Soils with clay-enriched subsoil |
| LX | lixisol | Lixisol | Soils with low-activity clays and exchangeable base cations equal to or greater than exchangeable Al. | Soils with clay-enriched subsoil |
| AL | alisol | Alisol | Soils with high-activity clays and exchangeable Al greater than exchangeable base cations. | Soils with clay-enriched subsoil |
| LV | luvisol | Luvisol | Soils with high-activity clays and exchangeable base cations equal to or greater than exchangeable Al. | Soils with clay-enriched subsoil |
| CM | cambisol | Cambisol | Moderately developed soils. | Soils with little or no profile differentiation |
| FL | fluvisol | Fluvisol | Soils with stratified fluviatile, marine or lacustrine sediments. | Soils with little or no profile differentiation |
| AR | arenosol | Arenosol | Very sandy soils. | Soils with little or no profile differentiation |
| RG | regosol | Regosol | Soils with no significant profile development. | Soils with little or no profile differentiation |