In soil classification, an Umbrisol is a soil with a dark topsoil and in which organic matter has accumulated within the mineral surface soil—in most cases with low base saturation—to the extent that it significantly affects the behaviour and utilization of the soil. Umbrisols are the counterpart of comparable soils with a high base saturation (Chernozems, Kastanozems and Phaeozems).
Many Umbrisols are under a natural or near-natural vegetation cover. Umbrisols occur above the actual tree line in the Andean, Himalayan and Central Asian mountain ranges; they are at lower altitudes in northern and western Europe where the former forest vegetation has been largely cleared, carry a vegetation of short grasses of low nutritional value. Coniferous forest predominates in Brazil (and in the United States). Umbrisols in tropical mountain areas in South Asia and Oceania are under montane evergreen forest. In the mountains of southern Mexico, the vegetation varies from tropical semi-deciduous forest to much cooler montane cloud forest.
Contour terraces and grassed waterways used for erosion control in Kansas.
The predominance of sloping land and wet and cool climate conditions restricts utilization of many Umbrisols to extensive grazing. Management focuses on the introduction of improved grasses and correction of the soil pH by liming. Many Umbrisols are susceptible to erosion. The planting of perennial crops and bench or contour terracing offer possibilities for permanent agriculture on gentler slopes. Where conditions are suitable, cash crops may be grown, e.g. cereals and root crops in the US, Europe and South America, or tea and cinchona in Indonesia. Highland coffee on Umbrisols demands high management inputs to meet its stringent nutrient requirements. In New Zealand, Umbrisols have been transformed into highly productive soils, used for intensive sheep and dairy farming, and production of cash crops.
Umbrisols occupy about 100,000,000 hectares (250,000,000 acres) throughout the world. In South America, Umbrisols are common in the Andean ranges of Colombia, Ecuador, Venezuela, Bolivia and Peru. They also occur in Brazil, in Lesotho and in South Africa. Umbrisols in North America are confined largely to the northwest Pacific seaboard. In Europe, Umbrisols occur along the northwest Atlantic seaboard, e.g. in Iceland, on the British Isles and in northwest Portugal and Spain. In Asia, they are found in the mountain ranges east and west of Lake Baikal, and on fringes of the Himalayas, notably in India, Nepal, China and Burma. Umbrisols occur at lower altitudes in eastern India, in Burma and in Sumatra. In Oceania, Umbrisols are found in the mountain ranges of Papua New Guinea and southeast Australia and in the eastern parts of South Island, New Zealand.
^IUSS Working Group WRB (2022). "World Reference Base for Soil Resources, fourth edition" (PDF). International Union of Soil Sciences, Vienna.
Further readingedit
W. Zech, P. Schad, G. Hintermaier-Erhard: Soils of the World. Springer, Berlin 2022, Chapter 4.3.3. ISBN978-3-540-30460-9
External linksedit
profile photos (with classification) WRB homepage
profile photos (with classification) IUSS World of Soils
April 12, 2024
umbrisol, soil, classification, soil, with, dark, topsoil, which, organic, matter, accumulated, within, mineral, surface, soil, most, cases, with, base, saturation, extent, that, significantly, affects, behaviour, utilization, soil, counterpart, comparable, so. In soil classification an Umbrisol is a soil with a dark topsoil and in which organic matter has accumulated within the mineral surface soil in most cases with low base saturation to the extent that it significantly affects the behaviour and utilization of the soil Umbrisols are the counterpart of comparable soils with a high base saturation Chernozems Kastanozems and Phaeozems Umbrisola Umbrisol profileUsed inWRBWRB codeUMProfileA B CParent materialWeathered silicic rockClimateOceanic otherUmbrisols develop in weathering material of siliceous rock citation needed They are found in mostly cool humid climates in mountainous regions with little or no moisture deficit including tropical and subtropical mountains Many Umbrisols are under a natural or near natural vegetation cover Umbrisols occur above the actual tree line in the Andean Himalayan and Central Asian mountain ranges they are at lower altitudes in northern and western Europe where the former forest vegetation has been largely cleared carry a vegetation of short grasses of low nutritional value Coniferous forest predominates in Brazil and in the United States Umbrisols in tropical mountain areas in South Asia and Oceania are under montane evergreen forest In the mountains of southern Mexico the vegetation varies from tropical semi deciduous forest to much cooler montane cloud forest Contour terraces and grassed waterways used for erosion control in Kansas The predominance of sloping land and wet and cool climate conditions restricts utilization of many Umbrisols to extensive grazing Management focuses on the introduction of improved grasses and correction of the soil pH by liming Many Umbrisols are susceptible to erosion The planting of perennial crops and bench or contour terracing offer possibilities for permanent agriculture on gentler slopes Where conditions are suitable cash crops may be grown e g cereals and root crops in the US Europe and South America or tea and cinchona in Indonesia Highland coffee on Umbrisols demands high management inputs to meet its stringent nutrient requirements In New Zealand Umbrisols have been transformed into highly productive soils used for intensive sheep and dairy farming and production of cash crops Contents 1 Distribution 2 Related terminology 3 References 4 Further reading 5 External linksDistribution edit nbsp Distribution of umbrisols Umbrisols occupy about 100 000 000 hectares 250 000 000 acres throughout the world In South America Umbrisols are common in the Andean ranges of Colombia Ecuador Venezuela Bolivia and Peru They also occur in Brazil in Lesotho and in South Africa Umbrisols in North America are confined largely to the northwest Pacific seaboard In Europe Umbrisols occur along the northwest Atlantic seaboard e g in Iceland on the British Isles and in northwest Portugal and Spain In Asia they are found in the mountain ranges east and west of Lake Baikal and on fringes of the Himalayas notably in India Nepal China and Burma Umbrisols occur at lower altitudes in eastern India in Burma and in Sumatra In Oceania Umbrisols are found in the mountain ranges of Papua New Guinea and southeast Australia and in the eastern parts of South Island New Zealand Related terminology edit Umbrisol is a Reference Soil Group of the World Reference Base for Soil Resources WRB 1 Many of such soils are classified in the USDA soil taxonomy as Great Groups of Entisols and Inceptisols and as Very dark humus soils in the Russian soil classification References editThis article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations April 2013 Learn how and when to remove this template message IUSS Working Group WRB 2022 World Reference Base for Soil Resources fourth edition PDF International Union of Soil Sciences Vienna Further reading editW Zech P Schad G Hintermaier Erhard Soils of the World Springer Berlin 2022 Chapter 4 3 3 ISBN 978 3 540 30460 9External links editprofile photos with classification WRB homepage profile photos with classification IUSS World of Soils Retrieved from https en wikipedia org w index php title Umbrisol amp oldid 1170808216, wikipedia, wiki, book, books, library,
