Ajay Kumar at 05:50, 23 August 2023

2023-08-23T05:50:05Z

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{{Short description|Type of soil}}
{{Infobox soil
|name=Entisol
|alternative_name=
|type=
|type_link=
|image=Entisol profile.jpg
|image_size=200px
|image_caption=Entisol profile showing little or no evidence of pedogenic horizon development
|horizons=
|composition_secondary=
|classification_system=[[USDA soil taxonomy]]
|parent_material=
}}

'''Entisols''' are [[soils]], as defined under [[USDA soil taxonomy]], that do not show any profile development other than an [[A horizon|A-horizon]] (or “A” horizon). Entisols have no diagnostic horizons, and are unaltered from their parent material, which could be unconsolidated sediment, or rock. Entisols are the most common soils, occupying about 16% of the global ice-free land area.

Because of the diversity of their properties, suborders of entisols form individual Reference Soil Groups in the [[World Reference Base for Soil Resources]] (WRB): [[psamment]]s correlate with [[arenosol]]s, and [[fluvent]]s with [[fluvisol]]s. Many [[orthent]]s belong to [[regosol]]s or [[leptosol]]s. Most wassents and aquic subgroups of other suborders belong to the [[gleysol]]s.<ref>{{Cite web|url = http://www.fao.org/3/i3794en/I3794en.pdf|title = World Reference Base for Soil Resources 2014, Update 2015|author=IUSS Working Group WRB|year = 2015|publisher = World Soil Resources Reports 106, FAO, Rome}}</ref>

In [[Australia]], most entisols are known as '''rudosols''' or '''tenosols'''.

== Causes of delayed or absent development ==
* Unweatherable parent materials – [[sand]], [[iron]] [[oxide]], [[aluminium]] oxide, kaolinite [[clay]].
* Erosion – common on shoulder [[slopes]]; other kinds also important.
* Deposition – continuous, repeated deposition of new parent materials by flood as [[diluvium]], [[aeolian processes]] which means by [[wind]], slope processes as [[colluvium]], [[mudflow]]s, other means.
* Flooding or saturation.
* Cold climate – must not be sufficiently cold in winter for [[permafrost]].
* Dry climate.
* Shallow to bedrock – may be rock resistant to [[weathering]], such as [[quartzite]] or [[ironstone]].
* Toxic parent materials – [[serpentinite|serpentine soil]], mine spoils, [[sulfide|sulfidic]] clays.

== Suborders ==
*'''[[Aquent]]s''' – heavily saturated or soaked soils, mostly present at [[riparian]] locations (such as river banks, tidal [[mudflats]], [[estuaries]], etc). Here, consistent saturation limits development.
*'''Fluvents''' – [[alluvial soils]], where development is prevented by repeated deposition of [[sediment]] during periodic [[flooding]] events; present in [[valleys]] or [[river deltas]], especially those with high sediment load.
*'''[[Orthents]]''' – shallow or "skeletal" soils; found at sites of recent [[erosion surface|erosion]] events, or very old landforms ''completely devoid of weatherable [[minerals]]''.
*'''[[Psamments]]''' – Entisols that are sandy (through all layers), and in which development is precluded by the impossibility of weathering the sand; formed from shifting or [[glacial]] [[sand dunes]].
*'''Wassents''' – Entisols that have a positive water potential at the soil surface for more than 21 hours of each day, in all years.

==Paleopedology==

Most [[fossil]] soils, before the development of terrestrial vegetation in the [[Silurian]], are entisols that show no distinct soil horizons. Entisols are common in the [[paleopedological record]] ever since the Silurian; however, unlike other soil orders ([[oxisol]], [[ultisol]], [[gelisol]], etc) they do not have value as indicators of climate. Orthents may, in some cases, be indicative of an extremely ancient landscape with very little soil formation (i.e., Australia today).

==See also==
*[[Illuvium]]
*[[Pedogenesis]]
*[[Pedology (soil study)]]
*[[Soil classification]]

==References==
* {{cite web|url=http://soils.usda.gov/technical/classification/orders/entisols.html |title=Entisols |publisher=USDA-NRCS |access-date=2006-05-14 |url-status=dead |archive-url=https://web.archive.org/web/20060509223339/http://soils.usda.gov/technical/classification/orders/entisols.html |archive-date=May 9, 2006 }}
* {{cite web|url=http://grunwald.ifas.ufl.edu/Nat_resources/soil_orders/entisols.htm |title=Entisols |publisher=University of Florida |access-date=2006-05-14 |url-status=dead |archive-url=https://web.archive.org/web/20040918224211/http://grunwald.ifas.ufl.edu/Nat_resources/soil_orders/entisols.htm |archive-date=September 18, 2004 }}
* {{cite web| url =http://soils.ag.uidaho.edu/soilorders/entisols.htm| title =Entisols| publisher =University of Idaho| access-date =2006-05-14| archive-url =https://web.archive.org/web/20060901063744/http://soils.ag.uidaho.edu/soilorders/entisols.htm| archive-date =2006-09-01| url-status =dead}}
{{Reflist}}

{{Soil type}}

[[Category:Pedology]]
[[Category:Types of soil]]

Entisol - Revision history

Ajay Kumar at 05:50, 23 August 2023