IS23

Location: Riverside

Australian Soil Classification: Epicalcareous-Endohypersodic, Self-Mulching, Grey VERTOSOL

Northcote Factual Key: Ug5.2
Great Soil Group: grey clay
Soil Type: Horsham Clay.

General Landscape Description: Plain (stagnant).
Geology: Quaternary Coonambidgal Formation: fluvial to lacustrine clays and sands

IS23 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Dark grey (10YR4/1); light clay; cracking and self-mulching surface condition; moderate subangular blocky structure; very strong consistence dry; slightly sticky consistence wet; very few (<2%) hard carbonate segregations; pH 7.9; sharp boundary to:	IS23 Profile
Subsoil
B2	10-55 cm	Greyish brown (2.5Y5/2); light clay; plastic; moderate coarse prismatic structure strong consistence dry; moderately sticky consistence wet; very few (<2%) hard carbonate segregations; pH 8.2.
B3k	55-115 cm	Pale olive (5Y6/3); medium clay; plastic; moderate coarse lenticular structure (slickensides); strong consistence dry; sticky consistence wet; few (2-10%) hard carbonate segregations; pH 8.6.

Chemical and Physical Analysis:

Horizon	Sample Depth cm	pH H₂O	EC dS/m	Sodium Chloride %	Exchangeable Calcium cmol-/kg	Exchangeable Magnesium cmol-/kg	Exchangeable Potassium cmol-/kg	Exchangeable Sodium cmol-/kg	Total Nitrogen %	Exchangeable Acidity cmol-/kg	Organic Carbon %	Permanent Wilting Point -1500^okPa	Coarse Sand %	Fine Sand %	Silt %	Clay %
Horizon	Sample Depth cm	pH H₂O	EC dS/m	Sodium Chloride %	Exchangeable Calcium cmol-/kg	Exchangeable Magnesium cmol-/kg	Exchangeable Potassium cmol-/kg	Exchangeable Sodium cmol-/kg	Total Nitrogen %	Exchangeable Acidity cmol-/kg	Organic Carbon %	Permanent Wilting Point -1500^okPa	Coarse Sand %	Fine Sand %	Silt %	Clay %
A1	0–10	7.9	0.42	0.07	18.3	7.5	2.1	1.4	0.17	3.7	1.84	21.6	8	29	10	50
B2	10–55	8.2	1.28	0.25	17.3	12.6	1.1	3.4	0.06	2.7	0.52	22.9	7	23	4	61
B3k	55–115	8.6	2.06	0.44	8.9	17.5	2	7.3	0.03	2.3	0.24	23.8	6	20	10	58

Management Considerations:

Cracking clay soil.
Alkaline profile.
Shallow to moderately deep surface soil, generally self mulching.
Subsoil is sodic, with high saline and magnesium levels in the deep subsoil.
Yellow hue (5Y) and pale colour in deep subsoil indicates reduced conditions, poor internal drainage.
Roots may penetrate upper subsoil, but difficult physical and chemical environment below 55 cm.
Landform element, plain; slow site drainage.

Profile Described By: John Martin, Nabil Badawy, Ron Cawood, Geoff Pope, John Galea, John Turner (1970).

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