MySoil: Shallow sandy duplexes (Moora to Kojonup)

Grey, red or yellow/brown sands over clay at <30 centimetres (cm) depth.

A stylised diagram of the soil profile showing the topsoil and subsoil layers for grey shallow sandy duplex. Grey sand over sandy clay loam to clay at <30cm.
Broad scale map (1:250 000) of the Moora to Kojonup Agzone showing the distribution of shallow sandy duplexes. Distribution is scattered with 25–50% and 10–25% near Wickepin, Cunderdin, Darkan and Cranbrook, while Clackline has mainly 3–10%.
Soil pit showing the profile of grey shallow sandy duplex in the Moora to Kojonup region. Grey sand over sandy clay loam to clay at <30cm.

Summary

Table 1 Shallow sandy duplexes summary
Occurrence Moora to Kojonup (8%)

Soil Groups of Western Australia (WA)

404 Grey shallow sandy duplex

406 Red shallow sandy duplex

408 Yellow/Brown Shallow sandy duplex
Also known as

Duplex (sand over clay)

Australian soil classifications

404 Grey, yellow or brown Sodosol, Grey, yellow or brown Chromosol

406 Red Chromosol, Red Sodosol

408 Yellow or Brown Chromosol, Yellow or Brown Sodosol

Distinguishing features

Topsoil

  • Grey, red and yellow/brown moderately acidic sands to 30cm.
  • Surface soils can be hardsetting (406).
  • Gravel (<20 %) can be present usually at the base of the topsoil (sand) layer.

Subsoil

  • Abrupt boundary change between sand and clay layers at depth < 30cm.
  • Clays often sodic, mottled and may appear as polyhedral columns.
  • Clay pH mainly neutral to alkaline but can also be acidic at depth (404,408).
  • Subsoils can be saline (406).

Constraints

The following data has been derived from actual site samples taken. These results are recorded in this Excel spreadsheet.

Table 2 Common management constraints key
Rating Implications
Not applicable (n/a)

No constraints identified
Minor

Minor constraint - reduces crop yields in some years
Major

Major constraint - reduces crop yields in most years
Severe

Severe constraint - will always reduce crop yields
Table 3 Management constraints for shallow sandy duplexes

Soil Group of WA

404 Grey shallow sandy duplex*

404 Grey shallow sandy duplex*

406 Red shallow sandy duplex*

406 Red shallow sandy duplex*

408 Yellow/Brown shallow sandy duplex*

408 Yellow/Brown shallow sandy duplex*
Constraints Topsoil Subsoil Topsoil Subsoil Topsoil Subsoil

Acidity and aluminium toxicity

 Minor Minor Minor n/a Minor

n/a
Salinity

n/a

 Minor

n/a

 Major

n/a

n/a
Sodicity and alkalinity

n/a

 Major

n/a

 Major

n/a

 Minor
Boron toxicity

n/a

n/a

n/a

 Major

n/a

n/a
Poor nutrient retention

n/a

n/a

n/a

n/a

n/a

n/a
Aggregate stability

n/a

 Major

n/a

 Minor

n/a

 Major
Compaction and hard layers

n/a

n/a

n/a

n/a

n/a

n/a
Hard setting and crusting

n/a

n/a

n/a

n/a

n/a

n/a
Water repellence

Minor

n/a

n/a

n/a

 Minor

n/a
Low plant available water Minor Minor

n/a

 Major

n/a

n/a
Water-logging (seasonal)

n/a

n/a

n/a

n/a

n/a

n/a
Wind erosion (seasonal)

n/a

n/a

n/a

n/a

n/a

n/a
Water erosion (seasonal)

n/a

n/a

n/a

n/a

n/a

n/a

*Note - Data derived from site identifications (ID's).

  • Soil Group of WA - 404 Grey shallow sandy duplex site ID includes: KLC 0799, FFS 0104.
  • Soil Group of WA - 406 Red shallow sandy duplex site ID includes: FFS 0107.
  • Soil Group of WA - 408 Yellow/Brown shallow sandy duplex Site ID include FFS 0089, FFS 0090, FFS 0102, FFS 0103, FFS 0105, FFS 0109, FFS 0110, MRA 0008, MRA 1184.

Further information

Department of Agriculture and Food (2013) Report card on sustainable natural resource use in agriculture, Department of Agriculture and Food, Western Australia.

Fulton, I and Lantzke, N (1993) Soils of the Northam Advisory District: The Darling Range and West Kokeby Zones. Bulletin No. 4257. Western Australian Department of Agriculture.

Lantzke, N (1992) Soils of the Northam Advisory District. Bulletin No. 4244. The Zone of Ancient Drainage. Western Australian Department of Agriculture.

Lantzke, N (1993) Soils of the Northam Advisory District. Bulletin No. 4245. The Zone of Rejuvenated Drainage. Western Australian Department of Agriculture.

Lantzke, N and Fulton, I (1993) Land Resources of the Northam Region. Series No.11. Western Australian Department of Agriculture.

McArthur, WM (2004) Reference Soils of South-western Australia (Reprint). Department of Agriculture, Western Australia.

Moore, G (2004) Soil Guide: A Handbook for Understanding and Managing Agricultural Soils. Bulletin 4343. Department of Agriculture, Western Australia.

Percy, H (2000) Katanning Area Land Resource Survey. Land Resources Series No. 16. Agriculture Western Australia.

Sawkins, D (2010) Landscapes and Soils of the Northam District. Bulletin 4803. Department of Agriculture and Food, Western Australia.

Sawkins, D (2010) Landscapes and Soils of the Narrogin District. Bulletin 4807. Department of Agriculture and Food, Western Australia.

Sawkins, D (2010) Landscapes and Soils of the Katanning District. Bulletin 4817. Department of Agriculture and Food, Western Australia.

Schoknecht, N and Pathan, S (2013) Soil Groups of Western Australia. Resource Management Technical Report 380. Department of Agriculture and Food, Western Australia.

Stoneman, TC (1990) An Introduction to the Soils of the Moora Advisory District. Bulletin 4182. Western Australian Department of Agriculture.

Stoneman, TC (1991) An Introduction to the Soils of the Narrogin Advisory District. Bulletin 4221. Western Australian Department of Agriculture.

Stoneman, TC (1991) An Introduction to the Soils of the Katanning Advisory District. Bulletin 4202. Western Australian Department of Agriculture.

Verboom, B and Galloway, P (2004). Corrigin Area Land Resource Survey. Land Resources Series No. 20. Department of Agriculture, Western Australia.

 

See also

MySoil

Further information

Soils

Topics

Page last updated: Wednesday, 18 November 2015 - 9:36am