Vertisol - Citizendia

Vertisol profile

In both the FAO and USA soil taxonomy, a vertisol is a soil in which there is a high content of expansive clay known as montmorillonite that forms deep cracks in drier seasons or years. USDA Soil Taxonomy developed by United States Department of Agriculture and the National Cooperative Soil Survey provides an elaborate classification of Expansive clay is a Clay that is prone to large volume changes that are directly related to changes in Water content. Montmorillonite is a very soft phyllosilicate mineral that typically forms in microscopic Crystals forming a clay. Alternate shrinking and swelling causes self-mulching, where the soil material consistently mixes itself, causing vertisols to have an extremely deep A horizon and no B horizon. A soil horizon is a specific layer in the Soil which measures parallel to the soil surface and possesses physical characteristics which differ from the layers above and A soil horizon is a specific layer in the Soil which measures parallel to the soil surface and possesses physical characteristics which differ from the layers above and (A soil with no B horizon is called an A/C soil). This heaving of the underlying material to the surface often creates microrelief known as gilgai.

Vertisols typically form from highly basic rocks such as basalt in climates that are seasonally humid or subject to erratic droughts and floods. In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. A drought is an extended period of months or years when a region notes a deficiency in its water supply A flood is an overflow of an expanse of water that submerges land a deluge Depending on the parent material and the climate, they can range from grey or red to the more familiar deep black (known as black earths in Australia). For a topic outline on this subject see List of basic Australia topics.

Vertisols are found between 50° N and 45° S of the equator. The equator (sometimes referred to colloquially as "the Line") is the intersection of the Earth 's surface with the plane perpendicular to the Major areas where vertisols are dominant are eastern Australia (especially inland Queensland and New South Wales), the Deccan Plateau of India, southern Sudan, Ethiopia and adjacent Chad (the Gezira), and the lower Parana River in South America. Queensland is a state of Australia, occupying the north-eastern corner of the mainland continent Sudan (officially the Republic of Sudan) ( السودان al-Sūdān is a country in northeastern Africa. NOTE This intro is the result of careful NPOV work Please do not make potentially controversial edits to it without first discussing on the talk page Chad (Tchad تشاد Tshād) officially known as the Republic of Chad, is a Landlocked country in Central Africa. This article is about the second-longest river in South America For the shorter river in Goiás, central Brazil see Paranã River The Paraná River Other areas where vertisols are dominant include southern Texas and adjacent Mexico, northeast Nigeria, Thrace, and parts of eastern China. Texas ( is a state geographically located in the South Central United States and is also known as the Lone Star State. The United Mexican States ( or commonly Mexico (ˈmɛksɪkoʊ () is a federal constitutional Republic in North America. Nigeria, officially named the Federal Republic of Nigeria, is a federal Constitutional republic comprising thirty-six states and one Federal Thrace (Тракия Trakiya or "Trakija" or Trakia, Θράκη Thráki, Trakya is a historical and geographic area in southeast Europe China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National

In their natural state, vertisols are covered with grassland or grassy woodland. Grasslands (also called greenswards) are areas where the Vegetation is dominated by Grasses ( Poaceae) and other Herbaceous (non-woody Ecologically a woodland is an area covered in trees differentiated from a Forest. The heavy texture and unstable behaviour prevents forest from growing. A forest is an area with a high density of Trees There are many definitions of a forest based on various criteria

The shrinking and swelling of vertisols can damage buildings and roads, leading to extensive subsidence. Vertisols are generally used for grazing of cattle or sheep. Cattle, colloquially referred to as cows, are domesticated Ungulates a member of the Subfamily Bovinae of the family It is not unknown for livestock to be injured through falling into cracks in dry periods. However, the shrink-swell activity allows rapid recovery from compaction.

When irrigation is available, crops such as cotton, wheat, sorghum and rice can be grown. Irrigation is an artificial application of water to the soil usually for assisting in growing crops Cotton is a soft staple Fibre that grows around the seeds of the cotton plant ( Gossypium sp Wheat ( Triticum spp is a worldwide cultivated grass from the Levant area of the Middle East. Sorghum is a genus of numerous species of grasses, some of which are raised for grain and many of which are used as Fodder plants either cultivated or as part Rice is a Cereal foodstuff which forms an important part of the diet of many people worldwide and as such it is a staple food for many Vertisols are especially suitable for rice because they are almost impermeable when saturated. Rainfed farming is very difficult because vertisols can be worked only under a very narrow range of moisture conditions: they are very hard when dry and very sticky when wet. However, in Australia, vertisols are highly regarded, because they are the only soils that are not always acutely deficient in available phosphorus. Phosphorus, (ˈfɒsfərəs is the Chemical element that has the symbol P and Atomic number 15 Some, known as crusty vertisols, have a thin, hard crust when dry that can persist for 2 to 3 years before they have crumbled enough to permit seeding.

In the USA soil taxonomy, vertisols are subdivided into:

Aquerts: Vertisols which are subdued aquic conditions for some time in most years and show redoximorphic features are grouped as Aquerts. Because of the high clay content the permeability is slowed down and aquic conditions are likely to occur. In general, when precipitation exceeds evapotranspiration ponding may occur. Under wet soil moisture conditions iron and manganese is mobilized and reduced. The manganese may be partly responsible for the dark color of the soil profile.

Cryerts (not classified as vertisols in the FAO classification): They have a cryic soil temperature regime. Cryerts are most extensive in the grassland and forest-grassland transitions zones of the Canadian Prairies and at similar latitudes in the Soviet Union.

Xererts: They have a thermic, mesic, or frigid soil temperature regime. They show cracks that are open at least 60 consecutive days during the summer, but are closed at least 60 consecutive days during winter. Xererts are most extensive in the eastern Mediterranean and parts of California.

Torrerts: They have cracks that are closed for less than 60 consecutive days when the soil temperature at 50 cm is above 8°C. These soils are not extensive in the U. S. , and occur mostly in west Texas, New Mexico, Arizona, and South Dakota, but are the most extensive suborder of Vertisols in Australia.

Usterts: They have cracks that are open for at least 90 cumulative days per year. Globally, this suborder is the most extensive of the Vertisols order, encompassing the Vertisols of the tropics and monsoonal climates in Australia, India, and Africa. In the U. S. the Usterts are common in Texas, Montana, Hawaii, and California.

Uderts: They have cracks that are open less than 90 cumulative days per year and less than 60 consecutive days during the summer. In some areas, cracks open only in drought years. Uderts are of small extent globally, being most abundant in Uruguay and eastern Argentina, but also found in parts of Queensland and the "Black Belt" of Mississippi and Alabama. Uruguay.(official full name in República Oriental del Uruguay;, Oriental Republic of Uruguay) is a country located in the southeastern part of South America For a topic outline on this subject see List of basic Argentina topics. Queensland is a state of Australia, occupying the north-eastern corner of the mainland continent Mississippi ( is a state located in the Deep South of the United States Alabama (formally the State of Alabama;) is a State located in the southern region of the United States of America.

References

Vertisols. USDA-NRCS. Retrieved on 2006-05-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1264 - Battle of Lewes: Henry III of England is captured in France making Simon de Montfort the
Vertisols. University of Florida. Retrieved on 2006-05-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1264 - Battle of Lewes: Henry III of England is captured in France making Simon de Montfort the
Vertisols. University of Idaho. Retrieved on 2006-05-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1264 - Battle of Lewes: Henry III of England is captured in France making Simon de Montfort the

References

See also