Agriculture Reference
In-Depth Information
> 10% of area
3 - 9% of area
Geraldton
< 2% of area
Kalgoorie
Perth
Bunbury
Esperance
Albany
Western
Australia
AUSTRALIA
Perth
100 0 100 200 300kilometres
Figure 9.2
Distribution of ironstone gravelly soils in southwest Western Australia.
shallow (less than 50 cm) depth. While presence of a calcrete pan is used as a class deÝnition at
the Great Group or Subgroup level in the Australian Soil ClassiÝcation, in the South Australian
context this feature warrants separation at the highest level. Discriminators within this group of
soils are the presence of Ýne earth carbonates above the calcrete, the presence of a more clayey
subsoil, structure of subsoil, and surface texture. All soils in the group have the overriding limitation
of restricted water holding capacity Ð the nine classes deÝned within the group separate other key
properties related to fertility, drainage, and erosion potential.
The system is easy to use and understand, has real practical implications for users of agricultural
land in South Australia, and complements the national system. The latter is essential for providing
the higher resolution capacity needed to satisfy the classiÝcation demands of a much wider user-
group over the whole continent.
