Site MP25
Group: Birchip Cropping Group
Location: Curyo
Australian Soil Classification: Epihypersodic, Pedal, Calcic CALCAROSOL.
General Landscape Description: Very gently undulating plain within the Culgoa Land System (Rowan and Downes, 1963).
Site MP25 Landscape
Soil Profile Morphology:
Surface Soil
| A1 | 0-10 cm | Dark brown (7.5YR4/4); heavy clay loam (sandy); hardsetting and massive; some surface cracking evident; very firm consistence dry; pH 8.2; sharp and wavy change to: |  Site MP25 Profile |
| Subsoil | |||
| B21 | 10-20 cm | Dark brown (7.5YR4/4); medium clay; moderate medium prismatic, parting to blocky structure; strong consistence dry; pH 9.3; clear change to: | |
| B22 | 20-50 cm | Brown (7.5YR5/4); medium clay; moderate medium blocky structure; strong consistence dry; contains a few soft carbonates; pH 9.7; clear change to: | |
| B31 | 50-100 cm | Reddish yellow (5YR6/8); heavy clay; pH 9.9. | |
Soil Profile Characteristics:
| pH | Salinity Rating | Sodicity | Dispersion | |
| Surface (A1 horizon) | moderately alkaline | very low | non-sodic | none1 |
| Subsoil (B21 horizon) | very strongly alkaline | low-medium | strongly sodic | slight |
| Deeper subsoil (at 75 cm) | extremely alkaline | low-medium | strongly sodic | strong |
 |  |  |
| Horizon | Horizon Depth (cm) | pH (water) | pH (CaCl2) | EC ds/m | NaCI % | Exchangeable Cations | Field Capacity pF 2.5 | Wilting Point pF 4.2 | Coarse Sand (0.2 - 2.0 mm) | Fine Sand (0.02 -0.2 mm) | Silt (0.002 -0.02 mm) | Clay (<0.002 mm) | |||
| Ca | Mg | K | Na | ||||||||||||
| meq/100g | |||||||||||||||
| A1 | 0-10 | 8.2 | 7.6 | 0.15 | 14.9 | 5.6 | 2 | 0.9 | 33 | 12 | 28 | 27 | 4 | 34 | |
| B21 | 10-20 | 9.3 | 8.4 | 0.44 | <0.05 | 12.3 | 12.6 | 1.6 | 5.9 | 47 | 22 | 24 | 15 | 4 | 45 |
| B22 | 20-50 | 9.7 | 9 | 0.76 | 0.05 | 5.8 | 16 | 2 | 12.1 | 57 | 24 | ||||
| B31 | 50-100 | 9.9 | 9.1 | 0.64 | <0.05 | 4.3 | 13.8 | 1.7 | 12 | ||||||
Management Considerations:
Surface (A) Horizon
- Although non-sodic, the surface soil disperses significantly after remoulding. This indicates that structural degradation (e.g. surface sealing, crusting, increased cloddiness) may occur if the soil is cultivated or overstocked in a moist to wet condition. Also, raindrop action on bare surface soil may also promote dispersion and result in surface sealing or crust formation
- Increasing organic matter levels will assist in improving surface soil aggregation and ameliorating the hardsetting condition. Organic matter will decline under cropping but can be improved by adopting practises such as minimum tillage, residue retention and utilising pasture rotations
- The upper subsoil is very strongly alkaline becoming extremely alkaline with depth. This indicates that phosphorus and trace elements such as iron, manganese, copper and zinc may be poorly available to plants
- The subsoil is strongly sodic and dispersive. The movement of water and plant roots is likely to be restricted as a result. The high level of exchangeable magnesium will also compound the deleterious effect of exchangeable sodium on subsoil structure
- The level of soluble salts is only low-medium in the deeper subsoil and is only likely to affect very salt sensitive species
© The State of Victoria, 1996 - 2009.
This document was last reviewed on 20/08/2009