Narrewillock Series

Soils included in this series have distinct texture contrasts between soft ‘non-hard setting’ A horizons and moderately to strongly pedal clayey subsoils. A2 ‘subsurface’ soil horizons are absent. The uppermost subsoil layer, that is at least 15 cm thick, is whole coloured and yellow, yellow-brown or yellow-grey. The soil reaction trend is alkaline.

In the present survey, this series includes two soil types and one phase.


Narrewillock Sandy Loam (NA sl)

Profile Morphology:

Surface Soil

• 10-15 cm thick.
• Strong brown to dark reddish brown.
• Loamy sand to sandy loam.

Subsoil

• Reddish brown to yellowish brown, gradually changing to yellowish red (occasionally slightly mottled) at about 60 cm.
• Heavy clay to sandy heavy clay.

Soil Inclusions

• Trace to slight amounts of soft and/or hard CaCO3 occur at about 60 cm.

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	0.017	*	3.5	5.9
B	9.1	0.123	0.044	16.4	31.7
C	9.5	0.240	0.095	19.6	36.2

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

Occurrence:

Narrewillock Sandy Loam usually occurs on the lower parts of sand sheets and in the interdune swales.

Phases:

Deep surface:

• The depth to the clayey subsoil is about 30 cm (range 20-50 cm).
• Occurs mainly on the lunettes and upper slopes in the undulating plains.

Narrewillock Sandy Clay Loam (NA scl)

Profile Morphology:

Surface Soil

• 10-15 cm thick.
• Brown to dark brown.
• Sandy clay loam.

Subsoil

• Reddish brown to yellowish brown.
• Heavy clay.

Soil Inclusions

• Trace to slight amounts of soft and/or hard CaCO3 occur at about 50 cm, gradually increasing up to moderate amounts at depth.

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	8.3	0.066	0.005	13.1	21.3
B	8.5	0.046	*	22.4	34.9
C	9.8	0.208	0.040	23.5	45.6

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

Occurrence:

Narrewillock Sandy Clay Loam occurs mainly on lunettes.