Location: Macalister Research Farm. | Australian Soil Classification: Vertic & Hypocalcic, Subnatric, Brown SODOSOL. |
Great Soil Group: Solodic. | Geology: Late Pleistocene fluvial sediments. |
General Landscape Description: Level plain. | Mapping Unit: Denison. |
Site Description: Dairy grazing paddock. |
Site GP31 Landscape |
Surface Soil | Site GP31 Profile | ||
A1 | 0-25 cm | Dark greyish brown (10YR4/2); very fine sandy clay loam; very firm consistence dry; pH 6.0; clear change to: | |
A2 | 25-35cm | Yellowish brown (10YR5/4) conspicuously bleached; clay loam; contains a few (5%) iron nodules; pH 6.1; clear and wavy change to: | |
Subsoil | |||
B21 | 35-60 cm | Strong brown (7.5YR5/6) with greyish brown (7.5YR5/2) mottles; light medium clay; moderate coarse blocky, parting to moderate fine polyhedral structure; friable consistence moist; contains a few (5%) manganese nodules (2-4 mm in size); pH 7.1; gradual and wavy change to: | |
B22 | 60-110 cm | Brown (7.5YR5/4); medium heavy clay; slickensides present; contains a few (5%) carbonate/silica nodules (up to 10 cm in size); pH 8.5: | |
B23 | 110+ cm | Weak red (2.5YR5/4) with slight strong brown (7.5YR5/8) mottles; medium clay; moderate coarse prismatic, parting to strong coarse blocky structure; strong consistence dry; pH 9.0. |
Horizon | pH | Salinity Rating | ||
Surface (A1 horizon) | Moderately Acid | Very Low | Non-Sodic | None1 |
Subsoil (B21 horizon) | Slightly Alkaline | Very Low - Low | Sodic | Slight2 |
Deeper subsoil (at 1 m) | Moderately Alkaline | Very Low - Low | Sodic | Complete |
The soil profile becomes increasingly alkaline with depth. | The surface is non-sodic. The subsoil is sodic throughout. | ||
The salinity rating is very low throughout the profile. | There is a sharp increase in clay at the A/B horizon interface. |
Horizon | Horizon Depth (cm) | pH (water) | pH (CaCl2) | EC 1:5 | Exchangeable Cations | |||
Ca | Mg | K | Na | |||||
meq/100g | ||||||||
A1 | 0-25 | 6 | 5.2 | 0.06 | 3.8 | 1.5 | 0.25 | 0.26 |
A2 | 25-35 | 6.1 | 5.2 | 0.08 | 2 | 2 | 0.38 | 0.36 |
B21 | 35-60 | 7.1 | 6.1 | 0.11 | 2.8 | 7 | 0.44 | 1.3 |
B22 | 60-110 | 8.5 | 7.6 | 0.21 | 2.8 | 8.2 | 0.4 | 2 |
B23 | 110+ | 9 | 8 | 0.2 | 2 | 6.6 | 0.3 | 2.4 |
Horizon | Horizon Depth (cm) | 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 | 0-25 | 28 | 10 | 2 | 21 | 48 | 27 |
A2 | 25-35 | 26 | 11 | 4 | 19 | 44 | 33 |
B21 | 35-60 | 33 | 19 | 3 | 9 | 28 | 60 |
B22 | 60-110 | 32 | 19 | 1 | 5 | 33 | 61 |
B23 | 110+ | 34 | 21 | 1 | 6 | 39 | 54 |