Gley

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gley

[glā]
(geology)
A sticky subsurface layer of clay in some waterlogged soils.

Gley

 

gleyed topsoil, the portion of the soil profile characterized by lack of structure, low porosity, and green, blue, dove-gray, or mixed dove-gray-red color. It is formed as a result of the gleying of soils, a complex set of processes predominantly microbiological and biochemical in nature, including reduction of mineral and organic substances with formation of unstable forms of oxides of iron, manganese, aluminum, and other elements accumulated in the soil; transformation of humic acids into fulvic acids; acidification of the soil reaction with entry into the absorbing complex of bivalent iron, hydrogen, and aluminum; destruction of alumosilicate minerals with neogenesis of clay minerals containing bivalent iron; and a number of other phenomena. It develops in various swamped and marshy soils in topsoils with difficult or no access to oxygen (under the influence of ground or surface waters). Gley exerts an adverse effect on the overwhelming majority of wild and cultivated plants. Reclamation of gleyed soils involves first of all drying them out—lowering the level of groundwater and eliminating excess surface waters. The term “gley” was first introduced into scientific literature by the Russian scientist G. N. Vysotskii (1905) and became international in soil science.

V. M. FRIDLAND

References in periodicals archive ?
4) wet: somewhat poorly drained, soil is wet at a shallow depth for long periods during the growing season, commonly there is a high water table and/or additional water from catchment seepage, semi-hydromorphic gley (epigleyic) soils;
5) peaty: poorly drained hydromorphic peaty gley soils (or histic gleysols), soil is wet in the superficial peat horizon periodically during the growing season or is wet for a long period, free water is commonly persistent at or near the surface;
Redoximorphic features (Fe mottles, Fe-Mn concretions, gley colors) are abundant all over the profile due to frequent waterlogging and shallow water table.
On the other hand, according to Parfitt and Kimble (1989) Al-rich allophanes may form in soils where the Si concentration in soil solution is low and where the pH is <6; they described Al-rich allophane (Al/Si ratio >3) in gley podzols in poorly drained acidic materials.