Psamment
In
Psamments cover 3.4% of the global land mass. They occur throughout the world, being especially abundant in the deserts of Africa and Australia and on the ancient landforms of eastern South America. Areas dominated by Psamments also occur in other humid regions, notably in Florida and Nebraska (the Sand Hills).
Psamments typically have very low water-holding capacities because the sand in the soil is not graded so that sands of varying coarseness are constantly mixed right through the soil. Because most sands are highly siliceous, Psamments are also extremely low in all essential
The vegetation on Psamments varies enormously owing to the variety of climates, but in many cases is remarkably well-adapted to the climate, as with the Fynbos of the Cape region in South Africa—famous for its remarkable biodiversity and the equally species-rich Kwongan of southwestern Western Australia. The campinas and kerangas are healthy forests typical of Psamments in South America and Borneo.
Few Psamments are farmed, and where they are, the cost is high because of the expense of
In USDA soil taxonomy, Psamments are divided into:
- Cryopsamments: Psamments that have a cryic soil temperature regime
- Quartzipsamments: other Psamments that have, in the 0.02 to 2.0 mm fraction within the particle-size control section, a total of more than 90 percent (by weighted average) resistant minerals
- Torripsamments: other Psamments that have an aridic (or torric) moisture regime
- Ustipsamments: other Psamments that have an ustic moisture regime
- Xeropsamments: other Psamments that have a xeric moisture regime
- Udipsamments: other Psamments.
See also
- Pedogenesis
- Pedology (soil study)
- Psammosere
- Soil classification
- Soil types
References
- ^ Unit 10: Terms (Psamment) Archived 2009-04-10 at the Wayback Machine at pals.iastate.edu
- Soil Survey Staff: Keys to Soil Taxonomy. 12th edition. Natural Resources Conservation Service. U.S. Department of Agriculture. Washington D.C., USA, 2014.
- IUSS Working Group WRB: World Reference Base for Soil Resources, fourth edition. International Union of Soil Sciences, Vienna 2022. ISBN 979-8-9862451-1-9 ([1]).
Further reading
- W. Zech, P. Schad, G. Hintermaier-Erhard: Soils of the World. Springer, Berlin 2022, Chapter 8.3.1. ISBN 978-3-540-30460-9
External links
- profile photos (with classification) WRB homepage
- profile photos (with classification) IUSS World of Soils