Aridisols

Aridisols (from Latin aridus, "dry") are CaCO3-containing soils of arid regions that exhibit subsurface horizon development. They are characterized by being dry most of the year and limited leaching. Aridisols contain subsurface horizons in which clays, calcium carbonate, silica, salts and/or gypsum have accumulated. Materials such as soluble salts, gypsum and CaCO3 tend to be leached from soils of moister climates. They are divided into seven suborders: Cryids, Salids, Durids, Gypsids, Argids, Calcids and Cambids.

They are used mainly for range, wildlife and recreation. Because of the dry climate in which they are found, they are not used for agricultural production unless irrigation water is available. Aridisols occupy approximately 12% of the Earth's ice-free land area and approximately 8.3% of the U.S.

A photo of aridisols
Aridisols have either: (1) an aridic soil moisture regime and a cambic, calcic, petrocalcic, gypsic, petrogypsic argillic, natric or salic horizon; or (2) a salic horizon, a high water for at least one month, and a soil moisture control section that is dry in some or all parts for most of the year. (USDA-NRCS)

Salids, Gypsids

Salids — Aridisols soluble salt accumulation; Gypsids — Aridisols with gypsum accumulation

Durids (Idaho)

Aridisols with a Si02 cemented subsurface horizon

Haplargid, Desert Pavement

Haplargids are a type of soil found in arid and semi-arid regions, characterized by a specific horizon where clays accumulate below the surface

Petroargids (New Mexico)

Petroargids are a classification of Aridisols, which are soils found in arid regions

Calcids (Idaho)

Aridisols with CaC03 accumulation