The Future of Soil Taxonomy - Soil Geography of the USA: A Diagnostic-Horizon Approach - page 308

Table 27.1 A comparison of
diagnostic horizons between
ST and the WRB ( boldface
indicates epipedon)

ST WRB

Albic Albic

Agric Anthraquic

Anthropic Anthric

Argillic Argic

Calcic Calcic

Cambic Cambic

(Permafrost soil characteristic) Cryic

(Durinodes soil characteristic) Duric

Oxic Ferralic

(Ortstein soil characteristic) Ferric

Folistic Folic

Fragipan Fragic

(Andic soil properties) Fulvic

Gypic Gypsic

Histic Histic

Plaggen Hortic

Agric Hydragric

Agric Irragic

Melanic Melanic

Mollic Mollic

Natric Natric

Argillic Nitic

Petrocalcic Petrocalcic

Duripan Petroduric

Petrogypsic Petrogypsic

(Plinthite soil characteristics) Petroplinthitic

(Plinthite soil characteristics) Pisoplinthitic

Plaggen Plaggic

(Plinthite soil characteristics) Plinthic

Salic Salic

Sombric Sombric

Spodic Spodic

Natric Takyric

[no equivalent] Terric

[no equivalent] Thionic

Umbric Umbric

(Slickensides soil characteristics) Vertic

Mollic Voronic

[no equivalent] Yermic

Ochric [no equivalent]

and terric horizons in the WRB (Table 27.1 ). The ochric epipedon is not used in the
WRB, possibly because the system does not differentiate between epipedons and
subsurface horizons.
A persistent criticism of ST is that climate is a soil-forming factor and should not
be used to classify soils at the suborder level (Webster 1968 ). The rejoinder to this