Australian Soil Classification: Epihypersodic-Endocalcareous, Self-Mulching, Black VERTOSOL | General Landscape Description: Basalt plains, gently undulating plan/rises |
Site Description: Gently simple slope, easterly aspect (lunette?) | Geology: Quaternary-Newer Volcanics |
Soil Profile Morphology:
A1 | 0-15cm | Very dark grey (10YR3/1 moist and 10YR4/1 dry); light medium clay; thin self-mulching surface; (note: in trench spoil this material had self-mulched to <5 mm peds); smooth-faced coarse blocky structure below surface; strong consistence, deep cracks to surface; pH 5.7; gradual change to: | SW87 Profile |
Subsoil | |||
B21ss | 15-50/70 cm | Black (2.5Y2.5/1 moist, dry); heavy clay; strong, coarse (>100 mm) irregular lenticular structure, prominent slickensides increasing in size with depth; pH 8.0; clear and wavy change to: | |
B22k | 50/70 cm+ | Olive brown (2.5Y4/3 moist) and dark yellowish brown (10YR4/6 moist) mottles; white soft calcium carbonate (CaCO3); medium clay to light medium clay; vertic; fine, pH 8.3. |
pH | Salinity Rating | Sodicity | Dispersion | |
Surface (A1 horizon) | Moderately Acid | Low | None | None1 |
Subsoil (B21 horizon) | Moderately Alkaline | Medium - High | Strongly Sodic | Strong |
Deeper subsoil (at 50+ cm) | Strongly Alkaline | Very High | Strongly Sodic | None2 |
1 complete dispersion after remoulding 2 Possibly due to level of soluble salts. |
Horizon | Horizon Depth (cm) | pH (water) | pH (CaCl2) | EC 1:5 | NaCl % | Exchangeable Cations | |||
Ca | Mg | K | Na | ||||||
meq/100g | |||||||||
A1 | 0-10 | 5.7 | 5 | 0.24 | 16 | 12 | 1.4 | 1 | |
Bss | 35-55 | 8 | 7.3 | 0.76 | 0.15 | 15 | 15 | 0.8 | 5.5 |
Bk | 60+ | 8.7 | 8.3 | 1.6 | 0.35 | 12 | 16 | 0.4 | 7.2 |
Horizon | Horizon Depth (cm) | Ex Al mg/kg | Ex Ac meq/100g | Field pF2.5 | Wilting Point pF4.2 | Coarse Sand (0.2- 2.0 mm) | Fine Sand (0.02- 0.2 mm) | Silt (0.002- 0.02 mm) | Clay (<0.002 mm) |
A1 | 0-10 | <10 | 16 | 48.5 | 28.2 | 9.2 | 19.6 | 14 | 44 |
Bss | 35-55 | 54 | 25.6 | 4.8 | 19.4 | 15 | 55.5 | ||
Bk | 60+ | 44.3 | 23.1 | 1.8 | 12.2 | 9 | 41 |