EGW113

Location: Benambra

Australian Soil Classification: Eutrophic, Brown, FERROSOL (stony)

Map Unit: Fraser (Component 1)
Previous Site Name: EG113

General Landscape Description: Plateau
Site Description: 2 – 5% slope
Land Use: Grazing on annual pasture
Native Vegetation: Grassy woodland
Geology: Tertiary (Neogene) basalt

Soil Profile Morphology:

Surface soil
A11	0 – 5 cm	Dark reddish brown (5YR3/2); clay loam; weak fine polyhedral structure; weak consistence dry; clear change to:
A12	5 – 30 cm	Reddish brown (5YR4/3); clay loam; moderate fine polyhedral structure; firm consistence dry; few (2 – 10%) medium rounded (6 – 20 mm) pebbles; gradual change to:
Subsoil
B21	30 – 60 cm	Dark reddish brown (2.5YR3/3); medium clay; strong medium polyhedral structure; very firm consistence dry; basalt pebbles increasing and becoming larger with depth; gradual change to:
R	60 cm - 1m+	Decomposing basalt rock

Key Profile Features:

• Gradual increase in texture down the soil profile.

Soil Profile Characteristics:

-	pH	Salinity	Sodicity	Dispersion
Surface soil (A12 horizon)	Slightly Acid	Very Low	Non-sodic	None
Subsoil (B2 horizon)	Slightly Acid	Very Low	Non-sodic	None

Chemical and Physical Analysis:

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC dS/m	Organic Carbon %	Free Fe2O3 % w/w	Exchangeable Aluminum ppm	Exchangeable Cations				Coarse Sand (0.2-2.0 mm) %	Fine Sand (0.02-0.2 mm) %	Silt (0.002-0.02 mm) %	Clay (<0.002 mm) %	Field Capacity % w/w	Wilting Point % w/w
								Ca	Mg	K	Na
								meq/100g
A12	5-30	6.2	5.5	0.07	2.7	3.4	<10	5.7	3.2	1.2	<0.05	13	34	32	22	17.5	4.4
B21	30-60	6.4	5.6	0.06		5.1	<10	9.3	7.0	1.5	0.07	5	23	27	43	28.4	10.3

Management Considerations

Whole Profile

• The profile is slightly acid throughout.
• These soils are very well drained due to their strongly developed subsoil structure.
• Plant available water is considered to be moderate, based on the laboratory data and the effective rooting depth of 70 cm.

Surface (A) Horizon

• The soil has moderate organic matter content. Organic matter will be better maintained under rotational grazing, which enables stronger pasture recovery, rather than set stocking.
• The nutrient holding capacity of the soil is moderate (based on the sum of the exchangeable cations). Organic matter is also important for maintaining soil fertility.
• Although the soils are fairly high in iron oxide (3.4%), the pH is high enough to minimise phosphorus fixation.

Subsoil (B) Horizon

• The friable nature of the subsoil allows deep penetration of plant roots.
• The friable nature of the subsoil together with the shallow depth to rock, can lead to problems with sealing of earth dams.

Soil Profile Described By: David Rees and Grant Boyle, 2000.