The Wimmera Region has the above Soil Orders that you can link to. These Soil Orders have been classified using the Australian Soil Classification. Broadscale overview soil maps are presented for each Soil Order and should only be used as a general indication of their distribution.
Sandy Soils | Vertosols | Calcarosols | Sodosols
There are four main Soil Categories in the Wimmera Region and these are listed below. Each of these Soil Categories contain one or more Soil Orders.
- Texture Contrast Soils
- Soils Lacking Strong Texture Contrast
- Cracking Clay Soils
- Sandy Soils
Texture Contrast Soils
Texture contrast soils are those that display strong texture contrast between the surface (A horizons) and the subsoil (B horizons) e.g. sand or loam over clay.
In the Wimmera Region, there is a range of soils with strong texture contrast, previously referred to as Duplex soils using the Northcote Factual Key.
Using the Australian Soil Classification there are three Soil Orders represented, based on subsoil chemistry (specifically pH):
- Sodosols
- Kurosols
- Chromosols
Sodosols have strong texture contrast between surface (A) horizons and the clay subsoil (B) horizons. They are widespread throughout the Wimmera and frequently occur on the older alluvial plains in the north and on sedimentary hills and rises.
Kurosols do not exist in the Wimmera.
There are some limited occurrences of Chromosols.
Soils Lacking Strong Texture Contrast
There are soils in the Wimmera Region which lack strong texture contrast between the surface and subsoil horizons. These soils have previously been referred to as Gradational soils using the Northcote Factual Key. Using the Australian Soil Classification they are classified as:
Calcarosols lack strong texture contrast and are calcareous throughout. They often contain calcium carbonate as soft or hard fragments. They are most common in the north-east of the region.
Cracking Clay Soils
These soils are referred to as Vertosols using the Australian Soil Classification. These are clay soils that shrink and swell, and crack as the soil dries. They are widespread throughout the Wimmera.
Sandy Soils
Sandy soils are common throughout much of the Wimmera. These can be soils which are sandy throughout (Rudosols and Tenosols) or soils which have deep sandy surface horizons overlying a clayey subsoil.