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Vertisols of the world A more detailed map of the global distribution of Vertisols. A vertisol is a Soil Order in the USDA soil taxonomy [1] and a Reference Soil Group in the World Reference Base for Soil Resources (WRB). [2] It is also defined in many other soil classification systems. In the Australian Soil Classification it is called ...
Soils with this shrink-swell capacity fall under the soil order of Vertisols. [6] As these soils dry, deep cracks can form on the surface, which then allows water to penetrate to deeper levels of the soil. [7] This can cause the swelling of these soils to become cyclical, with periods of both shrinking and swelling.
Expansive clay, also called expansive soil, is a clay soil prone to large volume changes (swelling and shrinking) directly related to changes in water content. [1] Soils with a high content of expansive minerals can form deep cracks in drier seasons or years; such soils are called vertisols.
The specific heat of pure water is ~ 1 calorie per gram, the specific heat of dry soil is ~ 0.2 calories per gram, hence, the specific heat of wet soil is ~ 0.2 to 1 calories per gram (0.8 to 4.2 kJ per kilogram). [90] Also, a tremendous energy (~584 cal/g or 2442 kJ/kg at 25 °C) is required to evaporate water (known as the heat of ...
A soil family category is a group of soils within a subgroup and describes the physical and chemical properties which affect the response of soil to agricultural management and engineering applications. The principal characteristics used to differentiate soil families include texture, mineralogy, pH, permeability, structure, consistency, the ...
Cation-exchange capacity (CEC) is a measure of how many cations can be retained on soil particle surfaces. [1] Negative charges on the surfaces of soil particles bind positively-charged atoms or molecules (cations), but allow these to exchange with other positively charged particles in the surrounding soil water. [2]
Because of the diversity of their properties, suborders of entisols form individual Reference Soil Groups in the World Reference Base for Soil Resources (WRB): psamments correlate with arenosols, and fluvents with fluvisols. Many orthents belong to regosols or leptosols. Most wassents and aquic subgroups of other suborders belong to the ...
Total water potential is a sum of matric potential which results from capillary action, osmotic potential for saline soil, and gravitational potential when dealing with downward water movement. Water potential in soil usually has negative values, and therefore it is also expressed in suction, which is defined as the minus of water potential ...