Sitemap

Walnut (Symbol: Wn)

EG201 | Profile No. 22 (Aldrick et al, 1992)

Geology
Holocene and Pleistocene alluvium.

Landform
Level plain with slopes generally less than 1% with a relief <9 m.

Terraced alluvial floors at low elevation, comprising flood plains, older alluvial terraces and alluvial fans, stream channels.

These terraces are confined to the Tambo River and its tributaries, mostly between 300 and 500 m.


Tambo valley flood plain north of Swifts Creek

Original vegetation
Dry valley forest.

Soils
Component 1: Soils on flood plains
Most of the soils of this map unit occur on the flood plains. Generally they are dark greyish brown deep fine sandy to silty loams and clay loams, but layers of coarser material such and stones and gravel may occur deeper in the subsoil (Site EG201). Parts of the valley have been dredged for gold bringing the stones to the surface.

Component 2: Soils on the older alluvial terraces
Older alluvial terraces are a minor component of this map unit and where they do occur are above the level of the current flood plain. The surface soils are commonly very dark greyish brown loamy sands to sandy clay loams overlying brown or reddish brown subsoils with variable texture and structure. No pits have been dug on this component.

Component 3: Soils on the alluvial fans.
These are a very minor component of this map unit and would vary greatly in colour, texture and rock fragments.

Component 4: The stream channel.
Bed and bank erosion is common along the stream channels.

Site EG201

Surface soil
A11	0 – 20 cm	Dark brown (10YR3/3); silty clay loam; strong fine (2 – 5 mm) granular structure; firm consistence dry; clear change to:
A12	20 – 45 cm	Very dark greyish brown (10YR3/2); silty clay loam; strong fine (2 – 5 mm) granular structure; firm consistence dry; diffuse change to:
A13	45 – 85 cm	Dark brown (10YR4/3); fine sandy clay loam; weak fine (2 – 5 mm) granular structure; firm consistence dry; clear change to:
Deep subsoil (buried soil)
D	85 – 105+ cm	Very dark grey (10YR3/1); clay loam; moderate medium (5 – 10 mm) polyhedral structure; firm dry
Key profile features Little colour or texture changes down the soil profile. Well structured upper profile.

• Plant available water capacity is considered to be low. This is based on an estimated effective rooting depth of 85 cm (i.e. the surface soil and the upper subsurface soil).

• The relatively deep surface soil is well structured.
• Infiltration of water into the well structured surface soil will be quite high. This horizon is also very well drained.
• The nutrient holding capacity of the surface (A1) horizon is moderate (based on the sum of the exchangeable cations). The organic matter for this soil is high which adds in both water and nutrient holding capacity.

• The upper subsurface soil is also well structured.

• Little colour or texture changes down the soil profile

This page contains material sourced from the Victorian Resources Online (VRO) website, originally published by the State Government of Victoria.

The content is provided under the Creative Commons Attribution 4.0 Australia licence (CC BY 4.0 AU).

This material is presented in an archived form and is no longer maintained or updated. It is provided for general information only and should not be relied upon as current advice.

This site is hosted by the Centre for eResearch and Digital Innovation (CeRDI), Federation University Australia. It is not endorsed by Agriculture Victoria.

Agriculture Victoria does not accept liability for any loss, damage or consequences arising from the use of, or reliance on, this material.