39. Sodic red texture contrast soils/Ridges with sand and flats: Low remnant ridge tops with aeolian sands and oriented swales

These soils have developed on Quaternary unconsolidated material, generally of riverine, aeolian and lacustrine origin in the North West Dunefields and Plains, south of the Little Desert. This soil has a slightly acidic surface and subsurface over a neutral to alkaline subsoil.

The surface soil is usually a dark yellowish brown, sandy loam, which is weakly structured. It sharply overlies a red sandy loam subsurface horizon, which is bleached and weakly structured. There is a sharp/abrupt change to a yellowish red medium clay upper subsoil horizon. This is moderately structured (with medium sized peds) and sodic to strongly sodic. This soil grades into mottled deeper subsoil, and/or weathered parent material. The profile depth is about 100 cm or more with variable depths of the surface horizons, generally 10 cm for the surface and 20 cm for the subsurface.

Notable features include:

• Texture contrast soil.
• Variable surface condition (generally hardsetting).
• Generally has a conspicuously bleached subsurface soil.
• Strong consistence (strength) of subsoil when dry.
• Strong consistence contrast (strength) between shallow surface soil and subsoil.
• The subsoil is sodic, often strongly sodic and dispersive.
• Free (visible) calcium carbonate may be present in subsoil.
• Mottling generally absent in upper subsoil.