CLRA05

Location: Indented Head, St Leonards district, Bellarine Peninsula

Australian Soil Classification: Eutrophic, Mottled-Subnatric, Yellow SODOSOL

General Landscape Description: Lower slope of Dunes
Geology: Quaternary Aeolian: coastal and inland dunes: dune sand, some swamp deposits.

CLRA5 Landscape. Low aeolian dunes near Indented Head

Soil Profile Morphology:

Surface Soil

A11	0–5 cm	Very dark grey (10YR3/1); sandy loam; very few (2–6 mm) subangular quartz gravels; weak medium sub-angular blocky structure; rough fabric; weak consistence dry; pH 6.0; smooth abrupt boundary to:	CLRA5 Profile
A12	5–20 cm	Very dark grey (10YR3/1); sandy loam; very few (2–6 mm) subangular quartz gravels; weak medium subangular blocky structure; rough ped fabric; weak consistence (dry); very few (6–60 mm) ferruginous nodules; pH 5.5; smooth clear boundary to:
A21	20–40 cm	Light brownish grey (10YR6/2); conspicuous bleach (10YR7/2); sand; very few (2–6 mm) subangular quartz gravels (2–6 mm); apedal massive structure; sandy fabric; loose consistence (dry); very few (6–60 mm) ferric nodules; pH 6.5; wavy clear boundary to:
A22	40–55 cm	Brown (10YR5/3); conspicuous bleach (10YR7/3); sand; few (2–6 mm) subangular quartz gravels (2–6 mm); apedal massive structure; sandy fabric; very weak consistence (dry); few (6–60 mm) ferric nodules; pH 6.5; wavy abrupt boundary to:
Subsoil
B21	55–70 cm	Brownish yellow (10YR6/6) with many very large red and light and dark brown (10R4/4, 10YR6/3, 10YR3/2) distinct mottles; medium clay; very few (2–6 mm) subangular quartz gravels; strong coarse columnar parting to medium prismatic structure; smooth ped fabric; common prominent clay skin and other cutans; very strong consistence (dry); pH 6.0; wavy clear boundary to:
BC	70–100 cm	Brownish yellow (10YR6/6) with many very large red and light and dark brown (10R4/4, 10YR6/3, 10YR3/2) prominent mottles; fine sandy clay; very few (2–6 mm) subangular quartz gravels; weak coarse columnar parting to medium prismatic structure; smooth ped fabric; few distinct clay skin and other cutans; strong consistence (dry); pH 7.0; wavy gradual boundary to:
C1	100–125 cm	Light grey (10YR7/2) with common large yellow (10YR6/6) prominent mottles; clayey fine sand; apedal massive structure; earthy fabric; very firm consistence (dry); pH 7.5; smooth clear boundary to:
C2	125–155+ cm	Light grey (10YR7/2) with common large yellow (10YR6/6) prominent mottles; clayey fine sand; apedal massive structure; earthy fabric; weak consistence (moderately moist); pH 7.7.

Soil Profile Characteristics:

Horizon	Sample Depth (cm)	pH (water)	pH (CaCl₂)	EC 1:5	Exchangeable Cations
					Ca	Mg	K	Na
					meq/100g
A11	0–5	5.2	4.5	0.1	3.5	1.2	0.24	0.34
A12	5–20	4.9	4.2	0.05	2.2	0.46	0.06	0.19
A21	20–40	5.2	4.5	<0.05	0.61	0.11	<0.05	<0.05
A22	40–55	5.8	5	<0.05	1	0.5	<0.05	0.15
B21	55–70	6.3	5.2	0.1	1.4	4.2	0.08	0.99
BC	70–100	6.8	5.8	0.14	0.5	3.1	0.06	1.2
C1	100–125	7.6	6.4	0.16
C2	125–135+	7.7	6.7	0.21

Horizon	Sample Depth (cm)	Exchangeable Aluminium mg/kg	Exchangeable Acidity cmol_c/kg	Field Capacity pF2.5	Wilting Point pF4.2	Coarse Sand (0.2- 2.0 mm)	Fine Sand (0.02- 0.2 mm)	Silt (0.002- 0.02 mm)	Clay (<0.002 mm)


A11	0–5	<10	8.5	16.1	7.5	31.8	54.4	1	11
A12	5–20	22	7.4	18.7	4.2	54.9	33.9	3.5	4
A21	20–40	23	3.3	9.3	1.3	50.4	42.6	3	3
A22	40–55	<10	4.3	9.7	2.9	59.9	28.8	5	6.5
B21	55–70		4.3	24.0	14.6	22.8	33.7	1	42.5
BC	70–100		2.5	19.1	11.0	2.2	63.8	9.5	22
C1	100–125
C2	125–135+

Management Considerations:

This soil has a strong texture contrast between the deep sandy soil and the subsoil which is sodic. It is important to maintain or improve the upper soil by increasing organic matter (particularly in the subsurface soil). The organic carbon content of the litter surface is 3.2% and the surface is 1.6%. It would be advisable not to bring the very dispersive subsoil [Emerson class 2(4)] to the surface as it would promote surface sealing (hardsetting) as well as adverse nutrient affects.

Maintenance of a vegetative cover is important for soil stability particularly where the surface soil is light and susceptible to water and wind erosion.

Root penetration of the clayey subsoil may be difficult with the hardsetting nature of the soil, coarse structure and nutrient imbalance (alkalinity with high sodicity and some salinity), but the sandy soil above provides a suitable physical medium for growth though with little water and nutrient holding capacity.

Profile Described By: David Rees (December 2002).