Alfisols are a soil order in USDA soil taxonomy. Alfisols form in semi-arid to humid areas, typically under a hardwood forest cover. They have a clay-enriched subsoil and relatively high native fertility. "Alf" refers to aluminium (Al) and iron (Fe). Because of their productivity and abundance, Alfisols represent one of the more important soil orders for food and fiber production. They are widely used both in agriculture and forestry, and are generally easier to keep fertile than other humid-climate soils, though those in Australia and Africa are still very deficient in nitrogen and available phosphorus. Those in monsoonal tropical regions, however, have a tendency to acidify when heavily cultivated, especially when nitrogenous fertilizers are used.
In the World Reference Base for Soil Resources (WRB), most Alfisols are classified as Luvisols or Lixisols, but some are classed as Retisols or Nitisols. Aqualfs are mainly Stagnosols or Planosols. Alfisols with a natric horizon are mainly Solonetz.[1]
Alfisols occupy around one-tenth of the Earth's ice-free land surface. They are dominant in many areas, such as the Ohio River basin in the United States, southern and unglaciated Western Europe, the Baltic region and central European Russia, the drier parts of Peninsular India, Sudan in Africa, and many parts of South America.
Alfisols have undergone only moderate leaching. By definition, they have at least 35% base saturation, meaning calcium, magnesium, and potassium are relatively abundant. This is in contrast to Ultisols, which are the more highly leached forest soils having less than 35% base saturation. In eastern North America, Alfisols are commonly found in glaciated areas while Ultisols are restricted to the areas south of the limit of maximum glaciation.
The fossil record of Alfisols begins in the Late Devonian. Probably owing to their fertility, they are the oldest forest soils; vegetation on weathered Oxisols, by contrast, is not known earlier than Middle Permian. Fossil Alfisols remain common from the Carboniferous and all periods since the Eocene.[citation needed]
^IUSS Working Group WRB (2015). "World Reference Base for Soil Resources 2014, Update 2015" (PDF). World Soil Resources Reports 106, FAO, Rome.
Alfisols are a soil order in USDA soil taxonomy. Alfisols form in semi-arid to humid areas, typically under a hardwood forest cover. They have a clay-enriched...
the soil at some time in most years. Some soil suborders, like udalf (alfisol) and udept (inceptisol), have an udic moisture regime. Pedogenesis Pedology...
Taxonomically, the Greek red soils belong to Rhodoxeralfs (red alfisol), Palexeralfs (well aged alfisols), Xerochrepts (xeric inceptisol), and Orthents. Red soils...
increasingly arid climates which cause former oxisols, ultisols or even alfisols to dry out in such a manner that a very hard crust is formed. This process...
that reflect major differences in the genesis of soils. The orders are: Alfisol – soils with aluminium and iron. They have horizons of clay accumulation...
existing carvings. The Mount Rushmore area is underlain by well drained alfisol soils of very gravelly loam (Mocmount) to silt loam (Buska) texture, brown...
(pH 3.6–7.4) and either a Histosol, Mollisol, Podsol, Oxisol, Ultisol, or Alfisol. Rainfall of 1,000–3,000 mm (39–118 in) per year is favored, but ʻōhiʻa...
soil aggregates show pressure faces. Nitisols correlate with the kandic alfisols, ultisols and inceptisols of the USDA soil taxonomy. These soils are found...
United States soil taxonomic system for the Alfisols soil order. Alf is the formative element in the Alfisol name, and refers to aluminium (Al) and iron...
(Azadirachta indica) on soil fertility and productivity of maize in a savanna alfisol.. Nutrient Cycling in Agroecosystems, 62(2), 115-122. Retrieved November...
Alfisols and Inceptisols occur widely in the US, but the circumstances of their occurrence would be difficult to characterize briefly. The Alfisols have...
survive frosts down to −43 °C. Some soils preferred by black walnut include alfisol and entisol soil types. Black walnut grows best on sandy loam, loam, or...
pedogenesis process under a chronosequence, once the soil develops into an alfisol, the Cambic horizon will develop into an argillic (Bt) horizon. They are...
in rocky areas and is grown on different soil associations, including alfisols, regosols, and lithosols. In other Himalayan locations, C. spinosa tolerates...
based on regression analysis involving chemical and physical properties in Alfisols and Ultisols of the state of Rio de Janeiro". Communications in Soil Science...
Europe. It is believed oxisols became vegetated later than ultisols or alfisols, probably because vegetation took a long time to adapt to the infertility...
of Michigan, Ohio in the United States and Ontario in Canada. It is an alfisol which is classified as an Orthic Gray Brown Luvisol under the Canadian...
Soils areloamy, well-drained, thermic Ultisols or moderately drained Alfisols, typically with sandy and loamy surface textures. In many areas of Ecoregion...
Within its native range it will grow on soils of Inceptisols, Ultisols, and Alfisols groups, but does not do well on compacted, clayey or eroded soils. Black...
sandy textured soils that often have been burned, plowed, and pastured. Alfisols are also present in these areas and contain a medium to high supply of...
be found in many different moist soils. Such soils include inceptisols, alfisols, spodosols and ultisols. The plants prefer deep, well drained soils that...
loamy. Four soil orders are found in the upstream river basin: ultisols, alfisols, inceptisols and entisols. With a major part of the river lying in the...
orders are found in Karnataka. Entisols, Inceptisols, Mollisols, Spodosols, Alfisols, Ultisols, Oxisols, Aridisols, Vertisols, Andisols and Histosols. Depending...
northern New York. White spruce most commonly grows in the soil orders of Alfisols and Inceptisols. Soil properties such as fertility, temperature, and structural...
types, including but not limited to ultisols, vertisols, inceptisols, alfisols, and mollisols. Similar to the marine nodules, concretion layers are defined...
loam/peat moss mixtures, to gravel or stone soils, but not very dry soils. Alfisol and Ultisol soil types are particularly favored due to being favorable...
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