Victorian Resources Online (archived)
CFTT8
| Location: Delburn. | Australian Soil Classification: Acidic, Mesotrophic, Brown DERMOSOL. |
| Great Soil Group: brown podsolic. | Geology: Mid-Tertiary sediments - probably includes basalt derived colluvium. |
| General Landscape Description: Simple 2% slope to north west. | Mapping Unit: Silver Creek. |
Surface Soil
| A1 | 0 – 15 cm | Dark brown (7.5YR3/4); clay loam; moderate coarse granular, parting to strong medium granular structure; very weak consistence moist; pH 4.9; gradual and smooth transition to: |  Site CFTT8 Profile |
| Subsoil | |||
| B21 | 15 – 30 cm | Dark brown (7.5YR3/4); light clay; moderate coarse polyhedral, parting to strong medium polyhedral structure; weak consistence moist; pH 4.9; diffuse and smooth transition to: | |
| B22 | 30 – 70 cm | Brown (7.5YR4/4); light medium clay; weak very coarse polyhedral structure; weak consistence moist; pH 4.1; gradual and smooth transition to: | |
| B23 | 70 – 120 cm | Yellowish brown (10YR5/4) with common distinct, strong brown (7.5YR5/6) and dusky red (7R4/3) mottles; medium clay; strong coarse subangular blocky, parting to strong medium subangular blocky structure; very firm consistence moist; pH 5.3; diffuse and smooth transition to: | |
| B24 | 120 – 190 cm | Yellowish brown (10YR5/4) with many, coarse sized, distinct, strong brown (7.5YR5/6) and dusky red (7R4/3) mottles, medium clay; strong coarse subangular blocky, parting to strong medium subangular blocky structure; very firm consistence moist. |
Notes: This is a redder version of the typical Silver Creek soil type.
Key Profile Features:
- Lack of strong texture contrast between surface (A) horizon and subsoil (B) horizons.
pH | Salinity Rating | |||
Surface (A1 horizon) | Very strongly acid | Very low | Non-sodic | none |
Subsoil (B21 horizon) | Very strongly acid | Very low | Non-sodic | none |
Deeper subsoil (at 1 m) | Strongly acid | Very low | Non-sodic | none |
 | The soil profile is very strongly to strongly acid throughout. |  | The levels of exchangeable aluminium are high in the upper subsoil and decrease below one metre depth. |
 | The salinity rating is very low throughout the soil profile. |  | The clay content increases gradually with depth down the soil profile. Clay contents are high throughout. |
Horizon | Horizon Depth (cm) | pH water | pH CaCl2 | EC 1:5 | Exchangeable Cations | Ex. Al mg/kg | Ex. Acidity meq/100g | Field Capacity pF 2.5 | Wilting Point pF 4.2 | Coarse Sand (0.2 -2.0 mm) | Fine Sand (0.02-0.2 mm) | Silt (0.002-0.02 mm) | Clay (<0.002 mm) | |||
Ca | Mg | K | Na | |||||||||||||
meq/100 g | ||||||||||||||||
A1 | 0-15 | 4.9 | 4.2 | 0.08 | 1.5 | 1.9 | 0.40 | 0.27 | 250 | 29 | 44.5 | 23.4 | 6 | 17 | 22 | 46 |
B21 | 15-30 | 4.9 | 4.3 | 0.08 | 1 | 1.9 | 0.21 | 0.26 | 270 | 28 | 41.2 | 23.9 | 4 | 16 | 20 | 50 |
B22 | 30-70 | 5.1 | 4.4 | 0.08 | 0.75 | 2.6 | 0.8 | 0.31 | 260 | 22 | 40.5 | 25.3 | 2 | 13 | 16 | 62 |
B23 | 70-120 | 5.3 | 4.6 | 0.07 | 0.92 | 4.2 | 0.07 | 0.43 | 100 | 15 | 47.1 | 31.6 | 4 | 11 | 13 | 68 |
Management Considerations:
- Pit excavated to 2 metres depth - no impeding layers observed. The upper soil profile is reasonably friable when moist and the deeper subsoil is well structured (parting to small subangular blocky peds) which will be favourable for root movement.
- Exchangeable aluminium levels are high in the very strongly acid upper soil profile. This may restrict the growth of aluminium sensitive species.
- Availability of some trace elements (e.g. copper, molybdenum) may be low in the very strongly acid soil profile.
- The soil profile has high wilting point values. This indicates that many plants will be unable to extract soil moisture when levels are low.
