Gypsisols in the

World Reference Base for Soil Resources The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. It is edited by a working group of the In ...

(WRB) are soils with substantial secondary accumulation of

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywal ...

(CaSO₄.2H₂O). They are found in the driest parts of the

arid A region is arid when it severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic. Most ...

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...

zone. In the

USDA soil taxonomy USDA soil taxonomy (ST) developed by the United States Department of Agriculture and the National Cooperative Soil Survey provides an elaborate classification of soil types according to several parameters (most commonly their properties) and in ...

they are classified as Gypsids (USDA Soil Taxonomy), in the Russian soil classification they are called ''Desert soils'' (USSR). Gypsisols are developed in mostly

unconsolidated Soil consolidation refers to the mechanical process by which soil changes volume gradually in response to a change in pressure. This happens because soil is a two-phase material, comprising soil grains and pore fluid, usually groundwater. When ...

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. All ...

colluvial Colluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combinati ...

and

aeolian deposits Aeolian commonly refers to things related to either of two Greek mythological figures: * Aeolus (son of Hippotes), ruler of the winds * Aeolus (son of Hellen), son of Hellen and eponym of the Aeolians * Aeolians, an ancient Greek tribe thought to ...

of base-rich

weathering Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement) ...

material. They are found on level to hilly land in arid regions. The natural vegetation is sparse and dominated by

xerophytic A xerophyte (from Greek ξηρός ''xeros'' 'dry' + φυτόν ''phuton'' 'plant') is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert such as the Sahara or places in the Alps or t ...

shrubs A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

and

trees In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are u ...

and/or ephemeral grasses These soils have ABC profiles. Accumulation of calcium sulphate, with or without carbonates, is concentrated in and below the B horizon. Deep Gypsisols located close to

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

resources can be planted to a wide range of crops. Yields are severely depressed where a petrogypsic horizon occurs at shallow depth. Nutrient imbalance, stoniness, and uneven subsidence of the land surface upon dissolution of gypsum in percolating (

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been devel ...

) water are further limitations. Irrigation canals must be lined to prevent the canal walls from caving in. Large areas of Gypsisols are in use for low volume

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...

. Gypsisols are exclusive to arid regions; their worldwide extent is probably of the order of 100 million hectares. Major occurrences are in and around Mesopotamia in desert areas in the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...

and adjacent

central Asian republics Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the former ...

, in the

Libya Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to the east, Suda ...

n and

Namib The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means "vast place". According to the broadest definition, the Namib stretches for more than along the Atlantic coasts of Angola, Nami ...

deserts, in southeast and central Australia and in the southwestern United States.

References

External links

profile photos (with classification)
WRB homepage
profile photos (with classification)
IUSS World of Soils {{Soil type Pedology Types of soil

See also

References

Further reading

External links