Entisols of the worldEntisols of stabilized sand dunes often fall into thePsamment soil suborder.Much of the fertile agricultural soils of theNile valley in Egypt are Entisols developed onalluvial materials (soil suborders Fluvent and Aquent)
Entisols aresoils, as defined underUSDA soil taxonomy, that do not show any profile development other than anA-horizon (or “A” horizon). Entisols have no diagnostic horizons, and are unaltered from their parent material, which could be unconsolidated sediment, or rock. Entisols are the most common soils, occupying about 16% of the global ice-free land area.
Aquents – heavily saturated or soaked soils, mostly present atriparian locations (such as river banks, tidalmudflats,estuaries, etc). Here, consistent saturation limits development.
Fluvents –alluvial soils, where development is prevented by repeated deposition ofsediment during periodicflooding events; present invalleys orriver deltas, especially those with high sediment load.
Orthents – shallow or "skeletal" soils; found at sites of recenterosion events, or very old landformscompletely devoid of weatherableminerals.
Psamments – Entisols that are sandy (through all layers), and in which development is precluded by the impossibility of weathering the sand; formed from shifting orglacialsand dunes.
Wassents – Entisols that have a positive water potential at the soil surface for more than 21 hours of each day, in all years.
Mostfossil soils, before the development of terrestrial vegetation in theSilurian, are entisols that show no distinct soil horizons. Entisols are common in thepaleopedological record ever since the Silurian; however, unlike other soil orders (oxisol,ultisol,gelisol, etc) they do not have value as indicators of climate. Orthents may sometimes indicate an extremely ancient landscape with minimal soil formation (i.e., Australia today).
