Wal Wal Series

The soil series is characterised by having a sporadically bleached A2 ‘subsurface' horizon, followed by grey to yellowish grey subsoil. In the present survey, this series consists of the following soil type:

Wal Wal Clay (WWc)

Profile Morphology:

Surface Soil (A1 horizon)

5-10 cm thick.
Dark reddish grey to brown or dark greyish brown.
Medium to heavy clay.
Very hard to extremely hard (dry), non-friable (moist), plastic and sticky (wet).

Sub-Surface Soil (A2 horizon)

3-10 cm thick.
Reddish grey to yellowish brown with a sporadic bleach. Bleaching may occur (in nests only) at the interface between the A and B horizons.
Soil texture and consistence are usually similar to those of the A1 horizon.

Subsoil

Greyish brown to reddish brown, changing gradually to pale brown or light reddish brown with depth. Slight colour mottling may occur in the deep subsoils.
Heavy clay.
Slightly friable to non-friable.
Trace to slight amounts of soft and/or hard CaCO₃; may increase up to light amounts in the deep subsoils.

Analytical Data for Selected Depths Down the Profile:

Depth	pH	Total Soluble Salts	Sodium Chloride	Moisture Retention @ 15-Bar	Moisture Retention @ 1/3-Bar
.	.	%	%	%	%
A	7.1	0.026	*	12.2	23.1
B	8.4	0.065	0.027	19.4	36.6
C	8.7	0.533	0.130	20.9	38.5

* Sodium Chloride contents were not measured and are expected to be very low (based on TSS <0.05%).

Occurrence:

Wal Wal clay occurs in the shallow depressions, low lying areas and slight gilgai depressions found on the gently undulating plains.

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