“Fluvisol”的意思、由来-百科全书

Fluvisol

FAO soil group

one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO) (soil). Fluvisols are found typically on level topography that is flooded periodically by surface waters or rising groundwater, as in river floodplains (floodplain) and deltas (delta) and in coastal lowlands. They are cultivated for dryland crops or rice and are used for grazing in the dry season. They occupy about 2.8 percent of the continental land area on Earth, mainly in the great river basins and deltas of the world (e.g., the Amazon basin and the Nile delta).

Fluvisols are technically defined by a weak or nonexistent surface horizon (uppermost layer) and by parent material derived from river, lake, or marine sediments that have been deposited at regular intervals or in the recent past. These soils exhibit a stratified profile that reflects their depositional history or an irregular layering of humus and mineral sediments in which the content of organic carbon decreases with depth. Wide variations in texture and mineral composition are observed. Fluvisols are related to the Inceptisol and Entisol orders of the U.S. Soil Taxonomy, wherever the latter occur on floodplains and deltas. Fluvisols are sometimes found in conjunction with Gleysols (Gleysol), a related FAO soil group formed under the influence of water.

词条	Fluvisol
释义	Fluvisol FAO soil group one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO) (soil). Fluvisols are found typically on level topography that is flooded periodically by surface waters or rising groundwater, as in river floodplains (floodplain) and deltas (delta) and in coastal lowlands. They are cultivated for dryland crops or rice and are used for grazing in the dry season. They occupy about 2.8 percent of the continental land area on Earth, mainly in the great river basins and deltas of the world (e.g., the Amazon basin and the Nile delta). Fluvisols are technically defined by a weak or nonexistent surface horizon (uppermost layer) and by parent material derived from river, lake, or marine sediments that have been deposited at regular intervals or in the recent past. These soils exhibit a stratified profile that reflects their depositional history or an irregular layering of humus and mineral sediments in which the content of organic carbon decreases with depth. Wide variations in texture and mineral composition are observed. Fluvisols are related to the Inceptisol and Entisol orders of the U.S. Soil Taxonomy, wherever the latter occur on floodplains and deltas. Fluvisols are sometimes found in conjunction with Gleysols (Gleysol), a related FAO soil group formed under the influence of water.
随便看	Martha McChesney Berry Martha McClellan Brown Martha Platt Falconer Martha Stewart Martha's Vineyard Martha Washington Martha Wollstein Marthinus Theunis Steyn Marthinus Wessel Pretorius Martial martial art martial law Martianus Minneus Felix Capella Martignac, Jean-Baptiste-Sylvère Gay, Viscount de Martigues Martim Afonso de Sousa Martin martin Martina Franca Martin Agricola Martin, A.J.P. Martin Alfred Hansen Martin Amis Martina Navratilova Martin Andersen Nexø