Agriculture Reference
In-Depth Information
Terra Rossa
(10-60 cm deep)
Groundwater
Rendzina
Hard “secondary”
carbonate layer
Black Earths
and swamp
Sandy limestone
Figure 9.10
A catenary soil sequence in the Coonawarra Region on Miocene limestone, influenced by
Pleistocene processes (courtesy of R. W. Fitzpatrick).
have been established during recent years, but which may have drainage problems
after a run of wet years. The best soil is the Terra Rossa on the high ridge. Its
profile is similar to a Brown Calcareous soil, that is, deeper than that of a Rend-
zina but with a pronounced red color due to residual ferric oxide impurities from
the weathering limestone and loess (fig. 9.11). The soil is well structured, with a
clay loam texture that provides an
AWC
of 17 mm per 0.1 m depth. However,
vine roots can penetrate the porous and fractured limestone below and extract wa-
ter at a relatively slow rate, in a way similar to that of vines grown on the lime-
Figure 9.11
A Terra Rossa soil profile in the Coonawarra Region, South Australia. Note the deep
solution hole in the limestone, filled in with red soil. Photograph by the author. See color
insert.
