# Gleysol > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Gleysol > Markdown URL: https://mediated.wiki/source/Gleysol.md > Source: https://en.wikipedia.org/wiki/Gleysol > Source revision: 1328500160 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Saturated soil type}} thumb|304x304px|Distribution of Gleysols A '''gleysol''' or '''gley soil''' is a [hydric soil](/source/hydric_soil) that unless drained is saturated with [groundwater](/source/groundwater) for long enough to develop a characteristic {{linktext|gleyic}} colour pattern. The pattern is essentially made up of reddish, brownish, or yellowish colours at surfaces of [soil particles](/source/ped) and/or in the upper [soil horizon](/source/soil_horizon)s mixed with greyish/blueish colours inside the peds and/or deeper in the soil. Gleysols are also known as ''Gleyzems'', ''meadow soils'', ''Aqu''-suborders of [Entisols](/source/Entisols), [Inceptisols](/source/Inceptisols) and [Mollisols](/source/Mollisols) ([USDA soil taxonomy](/source/USDA_soil_taxonomy)), or as ''groundwater soils'' and ''hydro-morphic soils''. The term '''gley''', or '''glei''', is derived from {{Langx|uk|глей|translit=hlei}}, and was introduced into scientific terminology in 1905 by the [Ukrainian](/source/Ukraine) scientist [Georgy Vysotsky](/source/Georgy_Vysotsky).{{Cite OED|term=gley|access-date=2022-12-27}} thumb|The clay on the right is exposed to air and is oxidized a reddish hue. The clay on the left is identical, but sealed in a glass jar for two weeks in an anaerobic setting, causing redox and color change to gley. Gleysols occur within a wide range of [unconsolidated materials](/source/compaction_(geology)), mainly [fluvial](/source/fluvial), [marine](/source/marine_(ocean)) and [lacustrine](/source/lake) [sediment](/source/sediment)s of [Pleistocene](/source/Pleistocene) or [Holocene](/source/Holocene) age, having [basic](/source/base_(chemistry)) to [acid](/source/acid)ic [mineralogy](/source/mineralogy). They are found in [depression](/source/depression_(geology)) areas and low [landscape](/source/landscape) positions with shallow groundwater. Wetness is the main limitation on agriculture of virgin gleysols;{{Fact|date=January 2025}} these are covered with natural [swamp](/source/swamp) [vegetation](/source/vegetation) and lie idle or are used for extensive [grazing](/source/grazing). Farmers use artificially-drained gleysols for [arable cropping](/source/agriculture), [dairy farming](/source/dairy_farming) and [horticulture](/source/horticulture). Gleysols in the [tropics](/source/tropics) and [subtropics](/source/subtropics) are widely planted with [rice](/source/rice). Gleysols occupy an estimated 720 million hectares worldwide. They are [azonal soils](/source/1938_USDA_soil_taxonomy) and occur in nearly all [climate](/source/climate)s. The largest extent of Gleysols is in northern [Russia](/source/Russia), [Siberia](/source/Siberia), [Canada](/source/Canada), [Alaska](/source/Alaska), [China](/source/China) and [Bangladesh](/source/Bangladesh). An estimated 200 million hectares of gleysols are found in the tropics, mainly in the [Amazon](/source/Amazon_Basin) region, equatorial [Africa](/source/Africa), and the coastal swamps of [Southeast Asia](/source/Southeast_Asia). [[Image:gleysoil.JPG|thumb|A [stagnohumic gleysoil](/source/stagnohumic_gleysoil) in a [forest plantation](/source/forest_plantation) in [Mid-Wales](/source/Mid-Wales), [United Kingdom](/source/United_Kingdom). The organic-rich [topsoil](/source/topsoil) is over a grey and orange mottled [subsoil](/source/subsoil) developed in glacial [till](/source/till) ("boulder clay").]] They exhibit a greenish-blue-grey [soil color](/source/soil_color) because of [anoxic](/source/anoxic_waters) [wetland](/source/wetland) conditions. On exposure, as the iron in the soil [oxidizes](/source/Oxidation) colors are transformed to a mottled pattern of reddish, yellow or orange patches. During [soil formation](/source/soil_formation) (''gleying''), the oxygen supply in the soil profile is restricted due to soil moisture at saturation. Anaerobic micro-organisms support cellular respiration by using alternatives to free oxygen as [electron acceptors](/source/electron_acceptors) to support [cellular respiration](/source/cellular_respiration). Where [anaerobic organisms](/source/anaerobic_organisms) [reduce](/source/redox) [ferric oxide](/source/ferric_oxide) to [ferrous oxide](/source/ferrous_oxide), the reduced mineral compounds produce the typical gleysoil color. [Green rust](/source/Green_rust), a [layered double hydroxide](/source/layered_double_hydroxide) (LDH) of Fe(II) and Fe(III) can be found as the mineral [fougerite](/source/fougerite) in gleysoils.{{cite journal |last1=Trolard |first1=Fabienne |last2=Bourrié |first2=Guilhem |last3=Abdelmoula |first3=Mustapha |last4=Refait |first4=Philippe |last5=Feder |first5=Frédéric |title=Fougerite, a new mineral of the pyroaurite-iowaite group: Description and crystal structure |journal=Clays and Clay Minerals |date=June 2007 |volume=55 |issue=3 |pages=323–334 |doi=10.1346/CCMN.2007.0550308 |bibcode=2007CCM....55..323T }}{{cite journal |last1=Génin |first1=Jean-Marie R. |last2=Aïssa |first2=Rabha |last3=Géhin |first3=Antoine |last4=Abdelmoula |first4=Mustapha |last5=Benali |first5=Omar |last6=Ernstsen |first6=Vibeke |last7=Ona-Nguema |first7=Georges |last8=Upadhyay |first8=Chandan |last9=Ruby |first9=Christian |title=Fougerite and FeII–III hydroxycarbonate green rust; ordering, deprotonation and/or cation substitution; structure of hydrotalcite-like compounds and mythic ferrosic hydroxide |journal=Solid State Sciences |date=May 2005 |volume=7 |issue=5 |pages=545–572 |doi=10.1016/j.solidstatesciences.2005.02.001 }} Gleysoils may be sticky and hard to work, especially where the gleying is caused by surface water held up on a slowly permeable layer. However, some [ground-water gley](/source/ground-water_gley) soils have [permeable](/source/Permeability_(fluid)) lower [horizons](/source/soil_horizons), including, for example, some sands in hollows within sand dune systems (known as slacks), and in some [alluvial](/source/alluvial) situations. Groundwater gleysoils develop where [drainage](/source/drainage) is poor because the [water table](/source/water_table) ([phreatic](/source/phreatic) surface) is high, whilst surface-water gleying occurs when [precipitation](/source/Precipitation_(meteorology)) input at the surface does not drain freely through the ground. A reducing environment exists in the saturated layers, which become mottled greyish-blue or greyish-brown due to its [ferrous iron](/source/ferrous_iron) and organic matter content. The presence of reddish or orange mottles indicates localised re-oxidation of ferrous salts in the soil matrix, and is often associated with root channels, animal burrows, or cracking of the soil material during dry spells. In the [World Reference Base for Soil Resources](/source/World_Reference_Base_for_Soil_Resources) (WRB),{{Cite web|url = https://wrb.isric.org/files/WRB_fourth_edition_2022-12-18.pdf|title = World Reference Base for Soil Resources, fourth edition|author = IUSS Working Group WRB|year = 2022|publisher = International Union of Soil Sciences, Vienna|access-date = 2023-08-16|archive-date = 2023-08-11|archive-url = https://web.archive.org/web/20230811210038/https://wrb.isric.org/files/WRB_fourth_edition_2022-12-18.pdf|url-status = live}} soils with [redox](/source/redox) processes due to ascending [groundwater](/source/groundwater) belong to the Reference Soil Group '''Gleysols'''. Soils with redox processes due to [stagnant water](/source/water_stagnation) are '''[Stagnosol](/source/Stagnosol)s''' and '''[Planosol](/source/Planosol)s'''. == See also == * [Pedogenesis](/source/Pedogenesis) * [Pedology (soil study)](/source/Pedology_(soil_study)) * [Soil classification](/source/Soil_classification) * [Anaerobic respiration](/source/Anaerobic_respiration) * [Fougerite](/source/Fougerite), the natural form of [green rust](/source/green_rust) * [Blue goo](/source/Blue_goo) * [Redox](/source/Redox) * [Redox gradient](/source/Redox_gradient) == External links == {{Wiktionary|gley}} * [https://wrb.isric.org/picture-gallery/ Profile photos (with classification)] {{Webarchive|url=https://web.archive.org/web/20231203094523/https://wrb.isric.org/picture-gallery/ |date=2023-12-03 }} WRB homepage * [https://www.iuss.org/index.php?article_id=73|title=IUSS Profile photos (with classification)] {{Webarchive|url=https://web.archive.org/web/20180930231253/https://www.iuss.org/index.php?article_id=73%7Ctitle=IUSS |date=2018-09-30 }} IUSS World of Soils == References == {{Reflist}} == Further reading == * {{cite book |doi=10.1007/978-3-540-30461-6 |title=Soils of the World |date=2022 |last1=Zech |first1=Wolfgang |last2=Schad |first2=Peter |last3=Hintermaier-Erhard |first3=Gerd |isbn=978-3-540-30460-9 }} {{Soil type}} {{DEFAULTSORT:Gley Soil}} Category:Pedology Category:Types of soil --- Adapted from the Wikipedia article [Gleysol](https://en.wikipedia.org/wiki/Gleysol) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Gleysol?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.