Mollisols are a soil order in USA soil taxonomy. Mollisols form in semi-arid to semi-humid areas, typically under a grassland cover. They have deep, high organic matter, nutrient-enriched surface soil. This fertile surface horizon, known as a mollic epipedon, results from the long-term addition of organic materials derived from plant roots. Mollisols occur in savannahs and mountain valleys. Because of their productivity and abundance, the Mollisols represent one of the more important soil orders.

Suborders

Albolls — wet soils; aquic soil moisture regime with an elluvial horizon

Aquolls — wet soils; aquic soil moisture regime

Borolls — cold climate; frigid or cryic soil temperature regime

Rendolls — lime parent material

Udolls — humid climate; udic moisture regime

Ustolls — subhumid climate; ustic moisture regime

Xerolls — Mediteranaean climate; xeric moisture regime

See also

Pedogenesis
Pedology (soil study)
Soil classification
Soil science
Soil type

External Links

SSSA glossary - mollisols (http://www.soils.org/cgi-bin/gloss_search.cgi?QUERY=Mollisols)
USDA - NRCS - mollisols (http://soils.usda.gov/technical/classification/orders/mollisols.html)
University of Idaho - mollisols (http://soils.ag.uidaho.edu/soilorders/mollisols.htm)
University of Florida - mollisols (http://grunwald.ifas.ufl.edu/Nat_resources/soil_orders/mollisols.htm)