Gleysols are azonal soils and occur in nearly all climates, from perhumid to arid, mainly in lowland areas where the groundwater comes close to the surface and the soil is saturated with groundwater for long periods of time.
Gleysols occupy an estimated 7.2 million km2 world-wide.
Conditioned by excessive wetness at shallow depth, this type of soil develops gleyic colour patterns made up of reddish, brownish or yellowish colours on ped surfaces or in the upper soil layers, in combination with greyish/bluish colours inside the peds or deeper in the soil profile. The main obstacle to utilisation of Gleysols is the necessity to install a drainage system, designed to either lower the groundwater table, or intercept seepage or surface runoff water. Adequately drained Gleysols can be used for arable cropping, dairy farming or horticulture.
Gleysols accounts for approximately 5.3% of the soil resources of the European Union. Gleysosl are abundant north of the Paris-Bucharest line, but can be found in smaller inclusions in the southern countries as well.