Location: Lara
Australian Soil Classification: Epicalcareous - Epihypersodic, Massive, Red VERTOSOL (moderate profile depth)
General Landscape Description: Near level plain.
Site Description: Broad flat ridge with easterly aspect slope <1%.
Geology: Quaternary Basalt.
Soil Profile Morphology:
Surface Soil
Ap | 0-12 cm | Brown (7.5YR4/3 moist); hardsetting surface condition; light clay; apedal structure; contains shelly material including intact shells; pH 7.9; clear and smooth change to: | SW103 Profile - Note: Surface stripped from soil profile. |
Subsoil | |||
B21t | 12-30 cm | Dark reddish brown (5YR3/3 moist); medium heavy clay; fine prismatic structure, parting to fine polyhedral; pH 9; clear and smooth change to: | |
B22ss | 30-60/75 cm | Dusky red (2.5YR3/3), becoming brown (7.5YR4/3) at depth; medium heavy clay; prominent slickensides (up to 30 cm across); pH 9.5; clear and wavy change to: | |
B23k | 60/75-80/100 cm | Reddish yellow (7.5YR6/8) becoming reddish yellow (7.5YR7/8) at depth; abundant soft calcium carbonate (CaCO3); irregular change to: | |
C | 80/100+ cm | Weathering vesicular soft greenish basalt; tongues of calcium carbonate (CaCO3) from B23k above; some biological activity present (ant nests). |
pH | Salinity Rating | |||
Surface (A1 horizon) | Slightly Alkaline | Low | Non-Sodic | None1 |
Subsoil (B21 horizon) | Strongly Alakaline | Low | Strongly Sodic | Moderate-Strong |
Deeper Subsoil (at 40-55 cm) | Very Strongly Alkaline | Medium-High | Strongly Sodic | Strong-Complete |
1 Strong dispersion after remoulding. |
The surface is slightly alkaline. The subsoil is strongly alkaline becoming very strongly alkaline at depth. | Salinity rating is low in the surface and upper subsoil becoming medium to high at depth. | The soil is non sodic in the surface and strongly sodic in the subsoil. | The clay content is high throughout the profile. |
Horizon | Sample Depth (cm) | pH (water) | pH (CaCl2) | EC 1:5 | NaCl % | Exchangeable Cations | |||
Ca | Mg | K | Na | ||||||
meq/100g | |||||||||
A1 | 0-10 | 7.9 | 7.3 | 0.2 | 21 | 4.1 | 1.5 | 0.8 | |
B21 | 15-30 | 9 | 8 | 0.42 | 0.02 | 15 | 8.8 | 1.4 | 7 |
B22 | 40-55 | 9.5 | 8.8 | 0.73 | 0.04 | 7.7 | 16 | 1.9 | 12 |
Horizon | Sample Depth (cm) | Organic Carbon % | Nitrogen % | Field Capacity 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 | 2.3 | 0.26 | 33.1 | 18.4 | 12 | 21 | 17 | 42 |
B21 | 15-30 | 55.3 | 29.6 | 5 | 14 | 11 | 65 | ||
B22 | 40-55 | 63.7 | 35.3 | 4 | 14 | 17 | 58 |