Gley soil


Gley soil

Gley soil in soil science is a type of hydric soil which exhibits a greenish-blue-grey soil color due to wetland conditions. On exposure to the air, gley colors are transformed to a mottled pattern of reddish, yellow or orange patches. During gley soil formation (a process known as 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. This is most often the case when the sesquioxide of iron, ferric oxide is reduced to ferrous oxide by the removal of oxygen. These reduced mineral compounds produce the gley soil color.

Gley soils 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 soils have permeable lower horizons, including some sands, for example in hollows within sand dune systems, known as slacks, and in some alluvial situations.

Groundwater gley soils develop where drainage is poor because the water table (phreatic surface) is high, whilst Surface-water gleying occurs when precipitation inputs at the surface do not drain freely through the ground. A reducing environment exists in the saturated layers, which become mottled greyish-blue or brown because of the content of ferrous iron and organic matter. 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.

Most soil classifications divide the gley soils into surface-water gleys (also known as stagnogleys) and gleys proper, or groundwater gleys, the former having a slowly pemeable lower subsoil, leading to a "perched" water table, the latter being in low ground or basin situations where the natural groundwater table is constantly high enough to influence the soil profile.

It is also a cheap alternative to clay.

ee also

*Anaerobic respiration
*Redox


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Look at other dictionaries:

  • Gley — may refer to:* Eugène Gley (1857 1930), French physiologist and endocrinologist * Gley soil, a type of hydric soilee also* Glay * Grey (disambiguation) …   Wikipedia

  • gley — [glā] n. [earlier glei < Ukrainian (cf. Russ glina, clay) < IE base * glei , to stick together > CLAY] a sticky, compact, clayey soil that sometimes develops in highly humid regions …   English World dictionary

  • Soil — For other uses, see Soil (disambiguation). A represents soil; B represents laterite, a regolith; C represents saprolite, a less weathered regolith; the bottommost layer represents bedrock …   Wikipedia

  • gley — /glay/, n. Geol. a mottled soil in which iron compounds have been oxidized and reduced by intermittent water saturation. Cf. gleization. [1925 30; < Ukrainian glei clayey earth; c. Byelorussian, Russ dial. glei, Serbo Croatian glêj; akin to CLAY] …   Universalium

  • gley — noun Usage: often attributive Etymology: Ukrainian gleĭ clayey earth; akin to Old English clǣg clay more at clay Date: 1927 a sticky clay soil or soil layer formed under the surface of some waterlogged soils • gleyed adjective …   New Collegiate Dictionary

  • gley — noun /ɡleɪ/ A type of hydric soil, sticky, greenish blue grey in colour and low in oxygen. Syn: gleysol, gleisol …   Wiktionary

  • gley — /gleɪ/ (say glay) noun a mottled soil, of a grey, blue, or rust colour, forming as a result of waterlogging; caused by anaerobic microorganisms acting on iron compounds in periods of water saturation. {Russian glei clay} –gleying, noun …   Australian English dictionary

  • gley — n. a tacky waterlogged soil grey to blue in colour. Etymology: Ukrainian, = sticky blue clay, rel. to CLAY …   Useful english dictionary

  • Hydric soil — A hydric soil is a soil that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part. [This definition (Federal Register, July 13, 1994) replaced the… …   Wikipedia

  • 1938 USDA soil taxonomy — The 1938 USDA soil taxonomy was a soil classification system adopted by the United States Department of Agriculture, now obsolete. The classification system used previously was developed and published in 1936 by C.F. Marbut, who was chief of the… …   Wikipedia


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