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Kastanozems
Kastanozem (also known as "chestnut soil") is one of the 32 Reference Soil Groups of the World Reference Base for Soil Resources (WRB). These soils are brighter than Chernozems, and are related to the Mollisols in the USDA soil taxonomy. They are rich in humus, and originally covered with early maturing native grasslands vegetation, which produces a characteristic brown surface layer in the first meter in depth. They have a relative high level of exchangeable calcium ions and secondary carbonates starting within 70 cm of the mineral soil surface. Kastanozems are found in relatively dry zones with 200 to 450 mm of rainfall a year. The name has two origins: the Russian term 'каштановые почвы', 'каштанозем', where 'каштановые' is a shade of brown derived from the word "каштан" (''kashtan''), "chestnut" and refers to the color of its husk Husk (or hull) in botany is the outer shell or coating of a seed. In the United States, the term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 International Union of Soil Sciences (IUSS). WRB, 4th edition (2022) Background History Since the 19th century, several countries developed national soil classification systems. During the 20th century, the need for an international soil classification system became more and more obvious. From 1971 to 1981, the Food and Agriculture Organization (FAO) and UNESCO published the Soil Map of the World, 10 volumes, scale 1 : 5 M). The Legend for this map, published in 1974 under the leadership of Rudi Dudal, became the FAO soil classification. Many ideas from national soil classification systems were brought together in this worldwide-applicable system, among them the idea of diagnostic horizons as established in the '7th approximation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chernozems
Chernozem ( ),; also called black soil, regur soil or black cotton soil, is a black-colored soil containing a high percentage of humus (4% to 16%) and high percentages of phosphorus and ammonia compounds. Chernozem is very fertile soil and can produce high agricultural yields with its high moisture-storage capacity. Chernozems are a Reference Soil Group of the World Reference Base for Soil Resources (WRB). Distribution The name comes from the Russian terms for black (чёрный ''čjornyj'') and soil, earth or land (земля ''zemlja''). Studies of the steppe soils of the Poltava region in the Russian Empire in 1883, conducted by geologist Vasily Dokuchaev, showed that the peasants called all soils by color, so the scientist began to use such names. Chernozem was black in color due to the large amount of organic matter. Dokuchaev was the first to describe the chernozem of the European part of the Russian Empire, and discovered its fertility. It is distinct from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollisols
Mollisol is a soil type which has deep, high organic matter, nutrient-enriched surface soil (A horizon), typically between 60 and 80 cm (24-31 in) in depth. This fertile surface horizon, called a mollic epipedon, is the defining diagnostic feature of Mollisols. Mollic epipedons are created by long-term addition of organic materials derived from plant roots and typically have soft, granular soil structure. Mollisols typically occur in savannahs and mountain valleys (such as Central Asia, and the North American Great Plains). These environments have historically been strongly influenced by fire and abundant pedoturbation from organisms such as ants and earthworms. It was estimated that in 2003, only 14 to 26 percent of grassland ecosystems remained in a relatively natural state (that is, they were not used for agriculture due to the fertility of the horizon). Globally, they represent ~7% of ice-free land area. As the world's agriculturally most productive soil order, the Mol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USDA Soil Taxonomy
USDA soil taxonomy (ST) developed by the United States Department of Agriculture and the National Cooperative Soil Survey provides an elaborate Soil classification, classification of soil types according to several parameters (most commonly their properties) and in several levels: ''Order'', ''Suborder'', ''Great Group'', ''Subgroup'', ''Family'', and ''Soil series, Series''. The classification was originally developed by Guy D. Smith, Guy Donald Smith, former director of the U.S. Department of Agriculture's soil survey investigations. Discussion A taxonomy is an arrangement in a systematic manner; the United States Department of Agriculture, USDA soil taxonomy has six levels of classification. They are, from most general to specific: order, suborder, great group, subgroup, family and series. Soil properties that can be measured quantitatively are used in this classification system – they include: depth, moisture, temperature, texture, structure, cation exchange capacity, base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown
Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors Orange (colour), orange and black. In the RGB color model used to project colors onto television screens and computer monitors, brown combines red and green. The color brown is seen widely in nature, wood, soil, human brown hair, hair color, eye color and Human skin color, skin pigmentation. Brown is the color of dark wood or rich soil. In the RYB color model, brown is made by mixing the three primary colors, red, yellow, and blue. According to public opinion surveys in Europe and the United States, brown is the least favorite color of the public; it is often associated with fecal matter, plainness, the rustic, although it does also have positive associations, including baking, warmth, wildlife, the autumn and music. Etymology The term is from Old English , in origin for any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chestnut
The chestnuts are the deciduous trees and shrubs in the genus ''Castanea'', in the beech family Fagaceae. The name also refers to the edible nuts they produce. They are native to temperate regions of the Northern Hemisphere. Description Chestnut trees are of moderate growth rate (for the Chinese chestnut tree) to fast-growing for American and European species. Their mature heights vary from the smallest species of chinkapins, often shrubby,''Chestnuts, Horse-Chestnuts, and Ohio Buckeyes'' . In Yard and Garden Brief, Horticulture department at University of Minnesota. to the giant of past American forests, '' C. dentata'' that could reach . Between these extremes ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Husk
Husk (or hull) in botany is the outer shell or coating of a seed. In the United States, the term husk often refers to the leafy outer covering of an Ear (botany), ear of maize (corn) as it grows on the plant. Literally, a husk or hull includes the protective outer covering of a seed, fruit, or vegetable. It can also refer to the exuvia of insects or other small animals left behind after ecdysis, moulting. The term ''husk'' dates to c.14, it is probably based on Middle Dutch word ''huusken'' meaning 'little house', which is derived from ''hūs'' meaning house. In cooking, hull can also refer to other waste parts of fruits and vegetables, notably the cap or sepal of a strawberry. Grains such as wheat and barley have husks. The grains are the entire seed of a plant. The seed of a grain (which the grain industry calls a "Seed, kernel") is made up of three key edible parts – the bran, the wheat germ, germ, and the endosperm – which are all protected by an inedible husk that pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
