Location: Werribee - Research Farm
Aust. Soil Class.: Vertic (& Sodic), Calcic, Brown DERMOSOL / Vertic, Mottled-Mesonatric, Grey SODOSOL
Northcote Factual Key:: Ug 5.25
Great Soil Group:: solodic
Previous Soil Type (Skene 1954): Austral clay loam (depressions at junction of basalt and alluvial deposits)
Maher and Martin (1979) map unit: 8/7
General Landscape Description: Level plain.
Site Description: Grazing paddock.
Geology: Quaternary alluvial (prior stream) and aeolian deposits/Quaternary basalt.
WP5 Landscape |
Soil Profile Morphology
Surface Soil | PPW8 Profile | ||
A1 | 0-5 cm | Dark brown (10YR3/3); heavy clay loam (fine sandy); hardsetting surface condition; very firm consistence (dry); many roots present; pH 5.2; clear change to: | |
Subsoil | |||
B21 | 5-30 cm | Dark yellowish brown (10YR4/4) with yellowish brown (10YR5/6) mottles; medium clay; strong coarse-medium blocky structure; strong consistence (dry); pH 5.9: | |
B22 | 30-60 cm | Light olive brown (2.5Y5/4 and 5/6); medium heavy clay; strong coarse blocky structure; strong cracking when dry; very strong consistence (dry); pH 7.7: | |
B23 | 60-80 cm | Light yellowish brown (2.5Y6/4); medium heavy clay; very strong consistence (slightly moist); few (5%) medium calcareous nodules (2-5 mm); few roots; pH 8.9: | |
B24 | 80-120 cm | Yellowish red (5YR5/6 & 5/8); medium clay; very strong consistence (slightly moist); few (5%) fine calcareous nodules and few (2 %) basalt fragments (2-5 cm); pH 8.8: | |
B25k | 120-140 cm | Yellowish red (5YR5/6); medium clay; many (20 %) fine calcareous nodules and very few (2 %) basalt fragments; pH 8.9. |
Note: In some areas, a discontinuous bleached subsurface horizon of variable depth (up to 50 cm) is present. This horizon is yellowish brown; conspicuously bleached (10YR 7/3 dry); very fine sandy clay loam with some rusty root channel mottling. This bleached horizon overlies a greyish brown (2.5Y 5/2) with light olive brown (2.5Y5/6) mottles heavy clay subsoil (B21) horizon. At depth, the subsoil becomes light olive brown (2.5Y 5/4), before becoming yellowish red (5YR 5/6) at 90 cm depth. This soil profile variation is related to the original gilgai microrelief. |
pH | Salinity Rating | |||
Surface (A1 horizon) | Strongly Acid | Low | Non-Sodic | None |
Subsoil (B21 horizon) | Moderately Acid | Low | Sodic | None1 |
Deeper subsoil (at 120-140 cm) | Strongly Alkaline | Very High | Strongly Sodic | None2 |
1Moderate to strong dispersion after remoulding. 2Slight dispersion after remoulding. Lack of dispersion likely due to high level of soluble salts deeper in the soil profile. |
Horizon | Horizon Depth (cm) | pH (water) | pH CaCl2 | EC dS/m | NaCl % | Exchangeable Cations | Boron (CaCl2) mg/kg | Ex Al mg/kg | Ex Ac meq/100g | Field pF2.5 | Wilting Point pF4.2 | Coarse Sand (0.2-2.0mm) | Fine Sand (0.02-0.2mm) | Silt (0.002-0.02mm) | Clay (<0.002mm) | |||
Ca | Mg | K | Na | |||||||||||||||
meq/100g | ||||||||||||||||||
A1 | 0-5 | 5.2 | 4.8 | 0.38 | 0.03 | 7.0 | 3.4 | 2.5 | 0.3 | <10 | 15 | 38.2 | 16.7 | 12 | 25 | 19 | 31 | |
B21 | 5-30 | 5.9 | 5.3 | 0.17 | 6.4 | 6.8 | 0.82 | 1.1 | <10 | 11 | 29.8 | 16.9 | 3 | 31 | 20 | 43 | ||
B22 | 30-60 | 7.7 | 6.9 | 0.27 | 0.04 | 9.4 | 14 | 1.2 | 4.2 | 44.8 | 23.3 | 3 | 21 | 20 | 54 | |||
B23 | 60-80 | 8.9 | 8.3 | 0.7 | 0.09 | 8.5 | 16 | 1.2 | 5.8 | 5.5 | 51.7 | 21.5 | 3 | 20 | 19 | 50 | ||
B24 | 80-120 | 8.8 | 8.4 | 1 | 0.15 | 6.3 | 19 | 1.4 | 7.7 | 15 | - | 24.8 | ||||||
B25k | 120-140 | 8.9 | 8.5 | 1.1 | 0.15 | 6.3 | 20 | 1.5 | 8.6 | 15 |
<2µm Clay Mineralogy | |||||||
Horizon | Depth cm | Quartz | Mica/Illite | Kaolin | Goethite | Orthclase | Smectite |
B22 | 30-60 | 6 | 23 | 34 | - | <1 | 37 |
B24 | 80-120 | 5 | 26 | 38 | - | <1 | 32 |
2µm Cation Exchange Capacity | ||||||||||||
Horizon | Depth cm | SiO2 % | Al2O3 % | MgO % | P2O5 % | K2O % | TiO2 % | MnO % | Fe2O3 % | BaO % | Sum % | CEC cmol/kg |
B22 | 30-60 | 48.7 | 22.8 | 1.2 | 0.4 | 2.0 | 1.2 | 0.0 | 9.2 | 3.7 | 89.1 | 49 |
B24 | 80-120 | 48.5 | 22.6 | 1.4 | 0.3 | 2.0 | 1.0 | 0.0 | 10.1 | 3.9 | 89.9 | 52 |