"Red clay" redirects here. For other terms, see Red clay (disambiguation) and Red dirt (disambiguation).
Ultisol
Red Clay Soil
A Ultisol profile
Used in
USDA soil taxonomy
Key process
weathering
Climate
tropical, humid subtropical, oceanic
Ultisol, commonly known as red clay soil, is one of twelve soil orders in the United States Department of Agriculture soil taxonomy. The word "Ultisol" is derived from "ultimate", because Ultisols were seen as the ultimate product of continuous weathering of minerals in a humid, temperate climate without new soil formation via glaciation. They are defined as mineral soils which contain no calcareous (calcium carbonate containing) material anywhere within the soil, have less than 10% weatherable minerals in the extreme top layer of soil, and have less than 35% base saturation throughout the soil. Ultisols occur in humid temperate or tropical regions. While the term is usually applied to the red clay soils of the Southern United States, Ultisols are also found in regions of Africa, Asia, Australia and South America.
In the World Reference Base for Soil Resources (WRB), most Ultisols are known as Acrisols and Alisols. Some belong to the Retisols or to the Nitisols. Aquults are typically Stagnosols or Planosols. Humults may be Umbrisols.[1]
^IUSS Working Group WRB (2015). "World Reference Base for Soil Resources 2014, Update 2015" (PDF). World Soil Resources Reports 106, FAO, Rome.
Ultisol, commonly known as red clay soil, is one of twelve soil orders in the United States Department of Agriculture soil taxonomy. The word "Ultisol"...
deciduous forests in cooler climates. They constitute 4% of soils worldwide. Ultisol – acid soils in the humid tropics and subtropics, which are depleted in...
achieve the best results. Red soils include multiple soil types (e.g. ultisols, alfisols, oxisols) that are classified as red soil when they develop a...
proportion of clay with the Cecil soil series a prime example of the consequent Ultisol great soil group. Granite is a natural source of radiation, like most natural...
become exposed to increasingly arid climates which cause former oxisols, ultisols or even alfisols to dry out in such a manner that a very hard crust is...
Red dirt or Red Dirt may refer to: Red soil Ultisol, or red clay soil Latosol, or tropical red earth Red dirt (music), a music genre Red Dirt (film),...
record ever since the Silurian; however, unlike other soil orders (oxisol, ultisol, gelisol, etc) they do not have value as indicators of climate. Orthents...
to 8.2. 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...
mollisols, through heavy cracking vertisols, infertile acid oxisols and ultisols, peaty histosols, to rocky andisols. Both plentiful sunshine and water...
monotonously in northwest and southwest directions. The soil is a gravelly Ultisol (Moormann et al., 1975).The major occupation of the majority of the people...
neutral (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...
Europe and to the Podzolic soils found in much of Canada's boreal forest.) Ultisols are rather extensive in warm, humid regions of the US. They tend to represent...
rainforests fall into two classifications which include the ultisols and oxisols. Ultisols are known as well weathered, acidic red clay soils, deficient...
America and Europe. It is believed oxisols became vegetated later than ultisols or alfisols, probably because vegetation took a long time to adapt to the...
regression analysis involving chemical and physical properties in Alfisols and Ultisols of the state of Rio de Janeiro". Communications in Soil Science and Plant...
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...
friable calcareous bedrock that breaks down into a fine crumb structure. Ultisol – A highly weathered, largely infertile, clay-based soil—usually brilliant...
clayey-skeletal, and loamy. Four soil orders are found in the upstream river basin: ultisols, alfisols, inceptisols and entisols. With a major part of the river lying...
carbon, nitrogen and phosphorus distribution in stable aggregate of an Ultisol under contrasting land use and management history. Bowen University, Official...
mixtures, to gravel or stone soils, but not very dry soils. Alfisol and Ultisol soil types are particularly favored due to being favorable to the vole's...
frequently flooded areas, they are classed as Spodosols, Psamments and Ultisols. Consequently, heavy fertilisation is required for agriculture or pastoral...
Physiography is distinct from the Arkansas Valley. Upland soils are mostly Ultisols that developed under oak-hickory and oak-hickory-pine forests. Today, forests...
Acrisols correspond to the Humult, Udult and Ustult suborders of the Ultisols and also to Oxisols with a kandic horizon and to some Alfisols. The Acrisols...
different moist soils. Such soils include inceptisols, alfisols, spodosols and ultisols. The plants prefer deep, well drained soils that range from loamy to clayey...
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