Victorian Resources Online (archived)
TOPCROP3
Location: Antwerp
Australian Soil Classification: Sodic, Hypercalcic, Brown DERMOSOL
General Landscape Description: Gently undulating plain.
Site Description: Cropping Paddock.
Geology: Quaternary deposits (Woorinen Formation).
Native Vegetation: Yellow Gum.
| TOPCROP3 Landscape - pit in foreground. In the background there is a rises landscape unit. |
Soil Profile Morphology:
Surface Soil
| Ap | 0-12 cm | Dark reddish brown (5YR3/2); sandy clay loam; weakly structured; weak to firm consistence dry; pH 7.4: |
 TOPCROP3 Profile |
| Subsoil | |||
| B21 | 12-25 cm | Dark reddish brown (5YR3/4) with reddish yellow (5YR6/8) mottles common; light clay; weak very coarse blocky, parting to weak coarse blocky structure; very firm consistence dry; pH 8.2: | |
| B22 | 25-60 cm | Strong brown (7.5YR5/6); light clay; weakly structured; earthy fabric; very firm consistence dry; few (10%) soft calcareous segregations and hard calcareous/silica nodules (3-15 mm); highly calcareous; very many macropores; pH 8.5: | |
| B23k | 60-100 cm | Reddish yellow (5YR6/6); light medium clay; weakly structured; very firm consistence dry; many (30%) soft calcareous and few (5%) hard calcareous nodules; moderately calcareous; pH 9.2: | |
| B24 | 100-130 cm | Reddish yellow (5YR6/6) with light yellowish brown (10YR6/4) mottles; medium heavy clay; strong very coarse prismatic, parting to moderate fine blocky structure; strong consistence dry; few (10%) soft calcareous segregations as well as manganese flecks; pH 9.7: | |
Key Profile Features:
- Strong texture contrast between surface (A) horizons and subsoil (B21) horizon.
Soil Profile Characteristics:
pH | Salinity Rating | |||
Surface (A1 horizon) | Slightly Alkaline | Low | Non-Sodic | None1 |
Subsoil (B21 horizon) | Moderately Alkaline | Low | Non-Sodic | None |
Deeper Subsoil (at 60-100 cm) | Very Strongly Alkaline | Low | Sodic | Moderate |
| The surface is slightly alkaline. The subsoil is moderately alkaline becoming very strongly alkaline with depth. | The profile has a low salinity rating throughout. | The surface is non sodic. The upper subsoil is non sodic becoming sodic with depth. | Boron levels are quite low throughout the profile. | Clay content increases with depth. |
Chemical and Physical Analysis:
Horizon | Horizon Depth (cm) | pH (water) | pH (CaCl2) | EC dS/m | NaCl % | Organic Carbon % | Nitrogen % | Boron mg/kg | Exchangeable Cations | Field Capacity 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 | ||||||||||||||||||
Ap | 0-12 | 7.4 | 7.0 | 0.20 | 1.7 | 0.14 | 1.1 | 16 | 2.4 | 1.5 | 0.29 | 22.7 | 9.9 | 37 | 29 | 11 | 19 | |
B21 | 12-25 | 8.2 | 7.7 | 0.19 | 0.94 | 0.07 | 1.4 | 28 | 3.9 | 1.0 | 0.30 | 27.3 | 15.0 | 26 | 26 | 11 | 33 | |
B22 | 25-60 | 8.5 | 7.9 | 0.23 | 1.3 | 31 | 4.2 | 0.55 | 0.27 | 30.6 | 15.8 | 20 | 21 | 8 | 27 | |||
B23k | 60-100 | 9.2 | 8.3 | 0.29 | <0.01 | 7.4 | 8.0 | 0.9 | 2.3 | 17 | 17 | 3 | 35 | |||||
B24 | 100-130 | 9.7 | 9.0 | 0.53 | <0.01 | 3.9 | 13 | 1.6 | 6.9 | |||||||||
Management Considerations:
- In general, management strategies for all soils should aim to increase organic matter levels in the surface soil; minimise the degradation of soil aggregates and porosity; promote the development of stable biopores; improve the calcium status of the ion exchange complex (particularly when sodium is a significant part), and break up any hardpans. Less frequent tillage; using less aggressive implements, and working the soil at optimum moisture conditions can all assist in maintaining soil aggregation and porosity as well as reducing the breakdown of organic matter.
- The deeper subsoil (from 60 cm depth) becomes extremely alkaline. This indicates that phosphorus and some trace elements such as iron, manganese, zinc and copper may be poorly available to plants and deficiencies may occur. Deficiencies can be determined by plant tissue analysis.
- The deeper subsoil (from 60 cm depth) becomes strongly sodic and dispersive. This will result in restricted root and water movement in the deeper subsoil.
