SW22

Location: Simpson

Australian Soil Classification: Humose-Acidic, Dystrophic, Grey DERMOSOL

Map Unit: Simpson/Tomahawk Creek Land System (Pitt, 1981).

General Landscape Description: Grazing paddock (dairy).
Site Description: Gently undulating plain
Geology: Tertiary - Neogene Hanson Plain Sand Formation.

SW22 landscape

Soil Profile Morphology:

Surface Soil

O	0-5 cm	Organic mat:	SW22 profile
A1	5-25 cm	Black (10YR2/1); loam; moderate coarse blocky, parting to moderate medium sub-angular block structure; weak consistence moist; pH 4.5; clear change to:
A2	25-45 cm	Very dark grey (10YR3/1); fine sandy loam; moderate coarse polyhedral structure; weak to firm consistence dry; pH 4.5; gradual change to:
Subsoil
B1	45-80 cm	Dark brown (7.5YR3/2); some rusty root channel mottling; light fine sandy clay loam; weak very coarse prismatic, parting to weak to moderate coarse blocky structure; firm consistence dry; pH 4.8; gradual change to:
B21	80+ cm	Brown (7.5YR5/2) with strong brown (7.5YR5/8) mottles and some dark stains along root channels; fine sandy clay loam; weak very coarse prismatic, parting to weak to moderate coarse blocky structure; firm to very firm consistence dry; pH 4.9.

NOTE: Some coffee rock in areas.

Key Profile Features:

Gradual increase in clay content with depth.
Cracks in subsoil.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Very Strongly Acid	Low	Non-Sodic	None
Subsoil (B21 horizon)	Very Strongly Acid	Very Low	Non-Sodic	None

The surface soil and subsoil is very strongly acid.

The salinity rating in the surface is low, the subsoil is very low.

The surface and upper subsoil is non-sodic.

The clay content is fairly constant throughout the profile.

Horizon	Horizon Depth (cm)	pH (water)	pH CaCl2	EC (dS/m)	Exchangeable Cations
					Ca	Mg	K	Na
					meq/100g
A1	5-25	4.5	3.8	0.14	6.5	0.6	0.1	0.1
A2	25-45	4.5	3.8	0.08	1.1	0.2	0.05	0.05
B1	45-80	4.8	4.3	0.06	0.2	0.05	0.05	0.05
B21	80+	4.9	4.2	<0.05	0.1	0.2	0.05	0.05

Horizon	Horizon Depth (cm)	Acidity meq/100g	Oxidisable Organic Carbon %	Total Nitrogen %	Field Capacity pF2.5	Wilting Point pF4.2	Coarse Sand (0.2-2.0 mm)	Fine Sand (0.02-0.2 mm)	Silt (0.002-0.02 mm)	Clay (<0.002 mm)


A1	5-25	10	9.6	0.49	30	21	19	42	12	10
A2	25-45				18	9	17	50	19	9
B1	45-80				16	5	19	50	17	10
B21	80+	5.5			16	5	19	48	20	15

Profile Described By: Mark Imhof and Austin Brown (May 1988).

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