Victorian Resources Online (archived)
CFTT4
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Location: Narracan East. | Australian Soil Classification: Bleached-Acidic, Magnesic, Brown DERMOSOL. |
| Great Soil Group: brown podsolic. | Geology: Mid-Tertiary sediments regarded as colluvium from basalts and earlier sediments. |
| General Site Description: Simple 2 -3% slope to east - north east. | Mapping Unit: Silver Creek. |
| Site Description: Eucalypt plantation. | |
Soil Profile Morphology:
Surface Soil
| A1 | 0-20 cm | Dark greyish brown (10YR4/2); fine sandy clay loam; moderate medium polyhedral structure; weak consistence moderately moist pH 5.1; clear and wavy transition to: |  Site CFTT4 Soil Profile |
| A2 | 20-40 cm | Light brownish grey (10YR6/2), conspicuously bleached with common, distinct light yellowish brown (10YR6/4) mottles; fine sandy clay loam; weak coarse polyhedral structure; weak consistence dry; pH 5.1; diffuse and smooth transition to: | |
| Subsoil | |||
| B21 | 40-80 cm | Very pale brown (10YR7/3), with common, medium sized, faint, yellow (10YR7/6) mottles; fine sandy light clay; weak coarse polyhedral structure; weak consistence dry; pH 5.1; clear and wavy transition to: | |
| B22 | 80-140 cm | Yellowish brown (10YR5/6), with common, medium, distinct, greyish brown (10YR5/2) mottles; medium clay; weak very coarse polyhedral structure; firm consistence moist pH 5.4; gradual and smooth transition to: | |
| B23 | 140-190 cm | Grey (10YR5/1), with many, medium, prominent, yellowish brown (10YR5/6) and strong brown (7.5YR4/6) mottles; medium clay; moderate coarse prismatic, parting to strong medium prismatic structure; very firm consistence moist; slickensides on ped faces. | |
Key Profile Features:
- Lack of strong texture contrast between surface (A) horizons and subsoil (B) horizons.
- Conspicuously bleached subsurface (A2) horizon.
pH | Salinity Rating | |||
Surface (A1 horizon) | Strongly acid | Very low | Non-sodic | none |
Subsoil (B21 horizon) | Strongly acid | Very low | Non-sodic | none |
Deeper subsoil (at 1 m) | Strongly acid | Very low | Non-sodic | none |
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The soil profile is very strongly acid throughout |
The salinity rating is low throughout the entire profile. |
The levels of exchangeable aluminium are reasonably high in the strongly acid surface soil and decrease in the subsoil. |
The clay content increases gradually with depth down the soil profile. |
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 | 0-20 | 5.1 | 4.4 | 0.06 | 2.2 | 1.2 | 0.15 | 1.17 | 110 | 16 | 26 | 7 | 1 | 46 | 35 | 14 |
A2 | 20-40 | 5.1 | 4.4 | <0.05 | 0.37 | 0.56 | <0.05 | 0.1 | 130 | 11 | 30 | 6 | 7 | 40 | 37 | 14 |
B21 | 40-80 | 5.1 | 4.5 | <0.05 | 0.29 | 0.95 | <0.05 | 0.08 | 64 | 6.1 | 25 | 6 | 6 | 40 | 38 | 17 |
B22 | 90-140 | 5.4 | 4.6 | <0.05 | <0.05 | 4.3 | 0.06 | 0.32 | 50 | 7.3 | 32 | 14 | 6 | 28 | 26 | 41 |
Management Considerations:
- No physical impeding layers were evident in the 2 metre deep soil pit. The upper soil profile has a weak consistence and is likely to be fairly conducive to root movement.
- The subsoil has very low levels of exchangeable calcium relative to other cations (i.e. calcium:magnesium ratio of < 0.1). This may result in calcium deficiency occurring for some plant species. The high levels of exchangeable magnesium may also inhibit uptake of nutrients such as calcium. In general, the soil profile has a relatively low nutrient holding capacity due in part to the high fine sand and silt contents.
- Availability of some trace elements (e.g. copper, molybdenum) may be low in the strongly acid soil profile.
