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Inceptisols are soils that exhibit minimal horizon development. They are more developed than Entisols, but still lack the features that are characteristic of other soil orders. They form quickly through alteration of parent material. They are older than entisols. They have no accumulation of clays, Fe, Al or organic matter.

Inceptisols are widely distributed and occur under a wide range of ecological settings. They are often found on fairly steep slopes, young geomorphic surfaces, and on resistant parent materials. Land use varies considerably with Inceptisols. A sizable percentage of Inceptisols are found in mountainous areas and are used for forestry, recreation, and watershed.

Globally, Inceptisols occupy ~9.8% of the ice-free land area. In the US, they occupy ~9.7% of the land area. These soils support the 20% of the world's population, the largest percentage of any of the soil orders.

Suborder Distribution

SUBORDERS

Aquepts - Inceptisols with a water table at or near the surface for much of the year. Most Aquepts formed in late-Pleistocene or younger deposits in depressions, on nearly level plains, or on flood plains. Found from the equator to latitudes with discontinuous permafrost. Aquepts may have almost any particle-size class except fragmental.

Anthrepts - Inceptisols that are more or less freely drained with either an anthropic or plaggen epipedon. Most of these soils have been used as cropland or other human useage. Anthrepts can have almost any temperature regime and almost any vegetation. Most have a cambric horizon.

Cryepts - Inceptisols of cold climates such as high mountains or higher latitudes. Vegetation is mostly conifers or mixed conifers and hardwoods. Few soils are cultivated. Cryepts do not have permafrost within 100 cm of the soil surface. Formed in loess, drift or alluvium, or in solifluction deposits, mostly late Pleistocene or Holocene in age. Moderatly extensive in the US, occuring in the high mountains of the West, southern Alaska as well as in other mountainous areas of the world.

Ustepts - Inceptisols are more or less freely drained soils that have an ustic moisture regime. Dominant moistures are recieved in summer precepitation. Formed mostly in Pleistocen or Holocene deposits. Some soils in steep slopes formed in older deposits. Native vegetation commonly grass but some supported trees. Most are used as cropland or pasture. In the USA, the Ustepts are most common on the Great Plains in Montana, Texas, and Oklahoma.

Xerepts - temperate Inceptisols with very dry summers and moist winters. More or less freely drained. Formed mostly in Pleistocene or Holocene deposits. The vegetation commonly is coniferous forest on soils with frigid or mesic temperature regimes and shrubs, grass, and widely spaced trees on the soils with a thermic temperature regime. Xerepts are of moderate extent in the US and are most common in the states of California, Oregon, Washington, Idaho, and Utah.

Udepts - Inceptisols of humid climates. More or less freely drained. Formed on nearly level to steep surfaces, mostly of late-Pleistocene or Holocene age. Most of the soils had, or now have forest vegetation, but some support shrubs or grasses. The Udepts of the USA are most extensive in the Appalachian Mountains, on the Allegheny Plateau, and on the west coast.

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