Soil type

Taxonomic unit

Map of global soil regions from the USDA

A soil type  is a taxonomic unit in soil science. All soils that share a certain set of well-defined properties form a distinctive soil type.[1] Soil type is a technical term of soil classification, the science that deals with the systematic categorization of soils. Every soil of the world belongs to a certain soil type. Soil type is an abstract term. In nature, you will not find soil types. You will find soils that belong to a certain soil type.

In hierarchical soil classification systems, soil types mostly belong to the higher or intermediate level. A soil type can normally be subdivided into subtypes, and in many systems several soil types can be combined to entities of higher category. However, in the first classification system of the United States (Whitney, 1909),[2] the soil type was the lowest level and the mapping unit.

For the definition of soil types, some systems use primarily such characteristics that are the result of soil-forming processes (pedogenesis). An example is the German soil systematics.[3] Other systems combine characteristics resulting from soil-forming processes and characteristics inherited from the parent material. Examples are the World Reference Base for Soil Resources[4] (WRB) and the USDA soil taxonomy.[5] Other systems do not ask whether the properties are the result of soil formation or not. An example is the Australian Soil Classification.[6]

A convenient way to define a soil type is referring to soil horizons. However, this is not always possible because some very initial soils may not even have a clear development of horizons. For other soils, it may be more convenient to define the soil type just referring to some properties common to the whole soil profile. For example, WRB defines the Arenosols by their sand content. Many soils are more or less strongly influenced by human activities. This is reflected by the definition of many soil types in various classification systems.

Because soil type is a very general and widely used term, many soil classification systems do not use it for their definitions. The USDA soil taxonomy has six hierarchical levels that are named order, suborder, great group, subgroup, family, and series. The WRB calls the first level Reference Soil Group. The second level in WRB is constructed by adding qualifiers, and for the result (the Reference Soil Group plus the qualifiers), no taxonomic term is used.

## See also

[edit]

* List of vineyard soil types

## References

[edit]

1. ^ W.E.H. Blum, P. Schad, S. Nortcliff (2018). Essentials of soil science. Borntraeger Science Publishers, Stuttgart.`{{cite book}}`: CS1 maint: multiple names: authors list (link)
2. ^ M. Whitney (1909). Soils of the United States. US Dept. Agric. Bur. Soil Bull. 55. Washington, D.C.
3. ^ Ad-hoc-AG Boden (2005). Bodenkundliche Kartieranleitung, 5. Auflage. Schweizerbart, Stuttgart.
4. ^ IUSS Working Group WRB (2022). "World Reference Base for Soil Resources, 4th edition". IUSS, Vienna.
5. ^ "Keys to Soil Taxonomy 2014". Archived from the original on 2018-11-28. Retrieved 2018-12-03.
6. ^ R.F. Isbell and the National Committee on Soil and Terrain (2016). "Australian Soil Classification, second edition (as Online Interactive Key)". CSIRO. Archived from the original on 2019-04-16. Retrieved 2018-12-03.

## External links

[edit]

* Soil classification systems
* A Compendium of On-Line Soil Survey Information Soil Classification for Soil Survey

* v
* t
* e

Soil science

* History
* Index

Main fields|

* Pedology
* Edaphology
* Soil biology
* Soil microbiology
* Soil zoology
* Soil ecology
* Soil physics
* Soil mechanics
* Soil chemistry
* Environmental soil science
* Agricultural soil science

Soil topics|

* Soil
* Pedosphere
* Soil morphology
* Pedodiversity
* Soil formation
* Soil erosion
* Soil contamination
* Soil retrogression and degradation
* Soil compaction
* Soil compaction (agriculture)
* Soil sealing
* Soil salinity
* Alkali soil
* Soil pH
* Soil acidification
* Soil health
* Soil life
* Soil biodiversity
* Soil quality
* Soil value
* Soil fertility
* Soil resilience
* Soil color
* Soil texture
* Soil structure
* Pore space in soil
* Pore water pressure
* Soil crust
* Soil horizon
* Soil biomantle
* Soil carbon
* Soil gas
* Soil respiration
* Soil organic matter
* Soil moisture
* Soil water (retention)

Soil type|

* v
* t
* e

Soil classification

World Reference Base
for Soil Resources (1998–)|

* Acrisols
* Alisols
* Andosols
* Anthrosols
* Arenosols
* Calcisols
* Cambisols
* Chernozem
* Cryosols
* Durisols
* Ferralsols
* Fluvisols
* Gleysols
* Gypsisols
* Histosol
* Kastanozems
* Leptosols
* Lixisols
* Luvisols
* Nitisols
* Phaeozems
* Planosols
* Plinthosols
* Podzols
* Regosols
* Retisols
* Solonchaks
* Solonetz
* Stagnosol
* Technosols
* Umbrisols
* Vertisols

USDA soil taxonomy|

* Alfisols
* Andisols
* Aridisols
* Entisols
* Gelisols
* Histosols
* Inceptisols
* Mollisols
* Oxisols
* Spodosols
* Ultisols
* Vertisols

Other systems|

* FAO soil classification (1974–1998)
* Unified Soil Classification System
* AASHTO Soil Classification System
* Référentiel pédologique (French classification system)
* Canadian system of soil classification
* Australian Soil Classification
* Polish Soil Classification
* 1938 USDA soil taxonomy
* List of U.S. state soils
* List of vineyard soil types
* PG-3 (Spanish classification system)

Non-systematic soil types|

* Sand
* Silt
* Clay
* Loam
* Topsoil
* Subsoil
* Soil crust
* Claypan
* Hardpan
* Gypcrust
* Caliche
* Parent material
* Pedosphere
* Laimosphere
* Rhizosphere
* Bulk soil
* Alkali soil
* Bay mud
* Blue goo
* Brickearth
* Brown earth
* Calcareous grassland
* Dark earth
* Dry quicksand
* Duplex soil
* Eluvium
* Expansive clay
* Fill dirt
* Fuller's earth
* Hydrophobic soil
* Loess
* Lunar soil
* Martian soil
* Mud
* Muskeg
* Paleosol
* Peat
* Prime farmland
* Quicksand
* Serpentine soil
* Spodic soil
* Stagnogley
* Subaqueous soil
* Takir
* Terra preta
* Terra rossa
* Tropical peat
* Yedoma

Types of soil

Applications|

* Soil conservation
* Soil management
* Soil guideline value
* Soil survey
* Soil test
* Soil governance
* Soil value
* Soil salinity control
* Erosion control
* Agroecology
* Liming (soil)

Related fields|

* Geology
* Geochemistry
* Petrology
* Geomorphology
* Geotechnical engineering
* Hydrology
* Hydrogeology
* Biogeography
* Earth materials
* Archaeology
* Agricultural science
* Agrology

Societies, Initiatives|

* Australian Society of Soil Science Incorporated
* Canadian Society of Soil Science
* Central Soil Salinity Research Institute (India)
* German Soil Science Society
* Indian Institute of Soil Science
* International Union of Soil Sciences
* International Year of Soil
* National Society of Consulting Soil Scientists (US)
* OPAL Soil Centre (UK)
* Soil Science Society of Poland
* Soil and Water Conservation Society (US)
* Soil Science Society of America
* World Congress of Soil Science

Scientific journals|

* Acta Agriculturae Scandinavica B
* Journal of Soil and Water Conservation
* Plant and Soil
* Pochvovedenie
* Soil Research
* Soil Science Society of America Journal

See also|

* Land use
* Land conversion
* Land management
* Vegetation
* Infiltration (hydrology)
* Groundwater
* Crust (geology)
* Impervious surface/Surface runoff
* Petrichor

* Wikipedia:WikiProject Soil
* Category soil
* Category soil science
* List of soil scientists

Authority control databases

National|

* Germany
* United States
* Israel

Other|

* Yale LUX

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template