Entisols in the context of Fluvisol

A gleysol or gley soil is a hydric soil that unless drained is saturated with groundwater for long enough to develop a characteristic gleyic colour pattern. The pattern is essentially made up of reddish, brownish, or yellowish colours at surfaces of soil particles and/or in the upper soil horizons 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, Inceptisols and Mollisols (USDA soil taxonomy), or as groundwater soils and hydro-morphic soils.

The term gley, or glei, is derived from Ukrainian: глей, romanized: hlei, and was introduced into scientific terminology in 1905 by the Ukrainian scientist Georgy Vysotsky.

Inceptisols are a soil order in USDA soil taxonomy. They form quickly through alteration of parent material. They are more developed than Entisols. They have no accumulation of clays, iron oxide, aluminium oxide or organic matter. They have an ochric or umbric horizon and a cambic subsurface horizon.

In the World Reference Base for Soil Resources (WRB), most Inceptisols are Cambisols or Umbrisols. Some may be Nitisols. Many Aquepts belong to Gleysols and Stagnosols.

Orthents are soils defined in USDA soil taxonomy as entisols that lack horizon development due to either steep slopes or parent materials that contain no permanent weatherable minerals (such as ironstone).

Typically, Orthents are exceedingly shallow soils. They are often referred to as skeletal soils or, in the United Nations FAO soil classification, as lithosols.

A Regosol in the World Reference Base for Soil Resources (WRB) is very weakly developed mineral soil in unconsolidated materials. Regosols are extensive in eroding lands, in particular in arid and semi-arid areas and in mountain regions. Internationally, Regosols correlate with soil taxa that are marked by incipient soil formation such as Entisols in the USDA soil taxonomy or Rudosols and possibly some Tenosols in the Australian Soil Classification.

The group of Regosols is a taxonomic rest group containing all soils that could not be accommodated in any of the other groups. Excluded from the Regosols are weakly developed soils that classify as Leptosols (very shallow soils), Arenosols (sandy soils) or Fluvisols (in recent alluvial deposits). These soils have AC-profiles. Profile development is minimal as a consequence of young age and/or slow soil formation.