Mollisols Alfisols Inceptisols Entisols

SOIL SUBORDERS

Example of an Udipsamment, which is an Entisol – A young poorly developed soil in a sandy glacial outwash plain.

SOIL SUBORDERS Mollisols - grassland soils with high base status

Albolls, Aquolls, Rendolls, Gelolls, Cryolls, Xerolls, Ustolls, andUdolls.

Alfisols - moderately leached soils with a subsurface zone of clay accumulation and >35% base saturation Aqualfs, Cryalfs, Udalfs, Ustalfs, and Xeralfs.

Inceptisols - soils with weakly developed subsurface horizons Aquepts, Anthrepts, Gelepts, Cryepts, Ustepts, Xerepts, and

Udepts.

Entisols - soils with little or no morphological development Wassents, Aquents, Arents, Psamments, Fluvents, andOrthents.

MOLLISOLS Grassland soils with high base status

Albolls - wet Mollisols with a light- colored horizon formed through Fe reduction

Aquolls - Mollisols with a water table at or near the surface for much of the year

Rendolls - shallow Mollisols over calcareous parent material

Gelolls - Mollisols of very cold cimates (mean annual soil temperature <0°C)

Cryolls - Mollisols of cold climates Xerolls - temperate Mollisols with very dry summers and

moist winters Ustolls - Mollisols of semiarid and subhumid climates Udolls - Mollisols of humid climates

MOLLISOL DIAGRAM

MOLLISOL SUBORDER DISTRIBUTION

EXAMPLE: RENDOLL Southeastern Minnesota Shallow soil Very dark A horizons

overlying calcareous sedimentary PM

Humid Regions: Mean annual precipitation is approximately 35 inches.

Highly calcareous parent material

Not extensive in the US.

ALFISOLS Moderately leached soils with a subsurface zone

of clay accumulation and >35% base saturation

Aqualfs - Alfisols with a water table at or near the surface for much of the year

Cryalfs - Alfisols of cold climates Ustalfs - Alfisols of semiarid and

subhumid climates Xeralfs - temperate Alfisols with very dry

summers and moist winters Udalfs - Alfisols of humid climates

ALFISOL DIAGRAM

ALFISOL SUBORDER DISTRIBUTION

EXAMPLE: AQUALF Mollic Albaqualf Central Missouri Parent Material: loess with clay

contents of 16% in the Ap horizon to 59% in the Bt horizon.

Abrupt increase in clay across the E-Bt horizon boundary.

Relatively fertile soils because of the high base saturation.

Clay-rich subsoil causes saturation during winter and spring problems for their use and management.

Used for corn, soybean, sorghum production with artificial drainage

INCEPTISOLS Soils with weakly developed subsurface horizons

Aquepts - Inceptisols with a water table at or near the surface for much of the year

Anthrepts - Inceptisols with evidence of human habitation and farming

Gelepts - Inceptisols of very cold climates (mean annual soil temperature <0°C)

Cryepts - Inceptisols of cold climates Ustepts - Inceptisols of semiarid and subhumid

climates Xerepts - temperate Inceptisols with very dry

summers and moist winters Udepts - Inceptisols of humid climates

INCEPTISOL DIAGRAM

INCEPTISOL SUBORDER DISTRIBUTION

EXAMPLE: UDEPT Lithic Eutrudept Northern Michigan Formed in glacial drift over

limestone Very shallow to bedrock. Note the irregular

boundary between the Bw horizon and the bedrock (R).

Although relatively fertile, too shallow for cultivation

Used for pasture land and timber production.

ENTISOLS Soils with little or no morphological development

Wassents - Entisols that are submerged for more than 21 hours every day

Aquents - Entisols with a water table at or near the surface for much of the year year

Arents - Entisols that have been disturbed and contain fragments of diagnostic horizons that are not arranged in any discernable order

Psamments - very sandy Entisols Fluvents - alluvial Entisols commonly found on

floodplains Orthents - common Entisols that don't meet

criteria of other suborders

ENTISOL DIAGRAM

ENTISOL SUBORDER DISTRIBUTION

EXAMPLE: FLUVENT SW Wisconsin Fluvial landscapes Stratified layers form

from deposition of fluvial sediment

Thick buried A horizon

Irregular decrease in organic carbon with depth.