Victorian Resources Online (archived)
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 | ||
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.
