Geoscience Reference
In-Depth Information
of the American system: the soil series used and known by farmers and extension-
ists (say Miami Series) remains Miami Series.
Alfi sols have the formation element
alf
. They occur mainly in humid and subhu-
mid climates. An increased clay content B horizon occurs within their profi le with-
out a leached horizon being developed. These soils are either identical or very close
to Luvisols, Nitisols, and Acrisols in World Reference Base (WRB) described in
Sect.
13.1
. The suborder Aqualfs is very similar to the WRB Stagnosols. An exam-
ple of one of the many Alfi sols is the suborder Ustalfs, great group Haplustalfs, and
subgroup Vertic Haplustalfs.
Andisols have the formation element
and
. The name is derived from the Japanese
words
an
meaning black and
do
meaning soil. They evolved on volcanic ash and
other volcanic materials. They are identical to WRB Andosols. An example is the
suborder Udands, great group Fulvudands, and subgroup Typic Fulvudands.
Aridisols have the formation element
id
. Their name has roots in the Latin
aridus
which means dry. They have been formed in arid climate and due to this factor they
have low content of humus. The prevailing evaporation over poor precipitations is
refl ected frequently by salt accumulation in subsurface horizons. They are similar to
soils in WRB system: Solonchaks, Solonetz, and some Arenosols. An example is
the suborder Gypsids, great group Petrogypsids, and subgroup Xeric Petrogypsids.
Entisols have the formation element
ent
derived from the word rec
ent
. They are
shallow soils without a subsurface horizon. This very simple soil profi le is due to
one of the following reasons: (a) short time for regular soil evolution, e.g., on fl ood-
plains regularly fl ooded by muddy river water; (b) action of continuous erosion;
(c) specifi c parent material like hard rocks, sands of deserts and semideserts, and
mined lands; and (d) in mountains. They are nearly identical with WRB Regosols,
and some of Entisols' great groups are similar to Leptosols. An example is the
suborder Fluvents, great group Udifl uvents, and subgroup Vertic Udifl uvents.
Gelisols have the formation element
el
. The name has the roots in the Latin
gelare
which means to freeze. The parent material is weakly weathered and soil
evolution is retarded or absolutely absent. Permafrost with typical honeycomb
structure and lenses of ice occur in the entire profi le. They are very similar to WRB
Cryosols. An example is the suborder Histels, great group Folistels, and subgroup
Lithic Folistels.
Histosols have the formation element
ist
. The name was derived from the Greek
histos
which means tissue. The topsoil is rich in organic matter; its content should
be above 24 %. Their properties are either similar or close to WRB Histosols. An
example is the suborder Folists, great group Ustifolists, and subgroup Lithic
Ustifolists.
Inceptisols have the formation element
ept
. Their name was derived from the
Latin
inceptus
which means start or beginning. They are soils with a weak develop-
ment of horizons except for the top A horizon, or epipedon in the US terminology.
These soils, usually young, display a soil profi le that lacks the characteristics of
other soils developed under the full assertion of soil-forming factors. They are nom-
inated at their lower-level taxonomy as similar to certain WRB Gleysols, Stagnosols,
