Agriculture Reference
In-Depth Information
ALL SOILS
Human-made soils
ANTHROPOSOLS
Dominated by organic materials
ORGANOSOLS
Negligible pedological organization
RUDOSOLS
Minimal pedological organization
TENOSOLS
Bs, Bhs or Bh horizon
PODOSOLS
Clay 35% in all horizons, cracks, slickensides
VERTOSOLS
Prolonged seasonal saturation
HYDROSOLS
Strong texture-contrast between A and B horizons
pH < 5.5 in
Non-sodic in upper B
Sodic in upper B
with pH
5.5
horizon with pH
5.5
upper B horizon
KUROSOLS
CHROMOSOLS
SODOSOLS
Lacking strong texture- contrast between A and B horizons
Calcareous through
High free iron B2
Structured B2
Massive B2
profile or below A1
CALCAROSOLS
FERROSOLS
DERMOSOLS
KANDOSOLS
Figure 9.1
Structure of the Australian Soil Classification.
A major conceptual challenge relates to disturbed soils. At present they can be allocated to
the suborder level of the Anthroposols soil order, or possibly as phases of other soil orders, such
as drained, bunded, or artiÝcially Þooded soils. The properties of such soil materials are not
found in current soil databases, but their inclusion should lead to further improvement as more
information is accumulated (e.g., a proposed classiÝcation of minesoils by Fitzpatrick and
Hollingsworth, 1995).
Other areas that require further development include the following:
¤ Better treatment of soil proÝles with seasonal or more frequent changes in salinity.
¤ Improved characterization of sodic soils. The current dependence on exchangeable sodium per-
centage without reference to soil solution electrolyte concentration or composition is insufÝcient
for predicting clay dispersion and related properties affecting soil behavior.
¤ Acid sulfate soils.
¤ReÝnements to the Tenosol Order (this is being incorporated into a revised edition due for
publication late in 2002).
Australian soil science and the classiÝcation schemes that reÞect it may be considered to be
Ñyoung science,Ò as compared to the discipline of geology and its rock stratigraphic classiÝcation
systems. Even when a tried and accepted general-purpose classiÝcation system is developed, there
