22. Cracking clay soils/Modern floodplains: Meander belt below flood level

These soils have developed on alluvium of Recent unconsolidated material in the Northern Riverine Plains, predominantly on the Wimmera River floodplain. The soil has a slightly acidic surface becoming
neutral and then more acidic with depth.

The surface soil is usually a light clay, massive (occasionally weakly structured). It occasionally overlies a bleached subsurface horizon. These soils have strong consistence (strength) depending on moisture condition. There is a clear change to a grey (occasionally light grey) heavy clay (occasionally light medium upper subsoil). It has moderate structure (with coarse to medium ped size) and often with very few carbonate nodules or soft segregations. This grades into lighter textured weathered alluvial parent material. The profile depth is about 160 cm or more with variable depths of the surface horizons, generally 5 cm for the surface.

Notable features include:

• Cracking clay soil, variable surface friability (massive or weak to moderate structure on cultivation).
• Strong consistence (strength) when dry; workability is more difficult than for than self-mulching soils.
• Whole coloured (grey) but has restricted soil drainage.
• Sodic subsoil, often strongly sodic at depth, but acidic trend at depth.