Soils of the North East Region

The North East 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.

Chromosols | Sodosols | Kurosols | Ferrosols | Dermosols | Organosols | Vertosols | Tenosols | Rudosols | Kandosols

There are four main Soil Categories in the North East 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
• Shallow 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 North East 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):

• Kurosols
• Chromosols
• Sodosols

Kurosols have clay subsoils which are strongly acid (i.e. pH <5.5 in water). Their surface texture ranges from loam to fine sandy loam over a clay subsoil. They are the most common of the texture contrast soils in the region and occur generally in the higher rainfall areas on a range of landform and rock types.

Chromosols have clay subsoils which are not strongly acid (i.e. pH >5.5 in water) and are non-sodic. Their surface texture ranges from loam to fine sandy loam over a clay subsoil. They are also most common in the drier north-western quarter of the region.

Sodosols have subsoils which are not strongly acid (i.e. pH >5.5 in water) but are sodic. Their surface texture ranges from sandy loam to clay loam over medium to heavy clay. They are not very common in the higher rainfall areas of the North East region and occur mainly in the drier north-western areas.

Soils Lacking Strong Texture Contrast

There are a number of soils in the North East 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:

• Dermosols
• Kandosols
• Ferrosols

Dermosols are non-texture contrast soils, which have moderately deep and well-structured subsoils. They are widespread throughout the North East region and are most commonly Red or Brown Dermosols. In the higher rainfall areas, they are generally strongly acid throughout the soil profile. They occur in many landscapes (from lower terraces to mountains) and have developed on a range of rock types.

Kandosols differ from Dermosols in that they have minimal structural development in the subsoil. They are found on the steep lower slopes in the northern half of the North East region.

Ferrosols are deep, well-structured and friable soils that have formed on basalt. They are high in free iron oxide and clay, and are generally strongly acid. Ferrosols occur on basalt hills and plateaus to the west of the King River.

Cracking Clay Soils

These soils are now referred to as Vertosols using the Australian Soil Classification. They are clay soils that shrink and swell causing seasonal cracking as the soil dries out. These soils occur in lower-lying areas and are not extensive in the North East region.

Shallow Soils

There are two shallow soils in the North East region as classified by the Australian Soil Classification:

• Rudosols
• Tenosols

Rudosols are young soils which show little development. These include some alluvial soils along the Ovens River.

Tenosols are shallow, weakly developed soils that show more profile development than Rudosols. They generally have low water holding capacity and fertility. In the North East region, Chernic Tenosols are common on high plains and plateaus and are characterised by organic rich surface horizons. Orthic Tenosols are usually shallow soils which have developed on hills and mountains.