SW43

Location: Laang

Australian Soil Classification: Bleached-Vertic, Eutrophic, Brown KUROSOL
General Landscape Description: Gently undulating plain.
Site Description: Grazing paddock (dairy).
Mapping Unit: Unit 40 (Maher and Martin, 1987).
Geology: Quaternary - Newer volcanics (basalt).

SW43 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-15 cm	Very dark greyish brown (10YR3/2); very fine sandy clay loam; moderate medium blocky, parting to moderate to strong fine polyhedral structure; weak structure moist; contains very few (2%) ferruginous nodules (2-4 mm in size); pH 5.4; clear change to:	SW43 Profile
A21	15-30 cm	Brown (10YR5/3), conspicuously bleached; fine sandy clay loam; weak to firm consistence moist; contains a few (5%) ferruginous nodules (2-10 mm in size); pH 5.5; clear change to:
A22	30-45 cm	Pale brown (10YR6/3), conspicuously bleached; fine sandy clay loam (heavy); moderate coarse polyhedral, parting to medium polyhedral structure; strong consistence, dry; contains a common (20%) amount of ferruginous nodules (2-5 mm in size); pH 5.8; clear change to:
Subsoil
B21	45-60 cm	Yellowish brown (10YR5/4) with a few (10%) strong brown (7.5YR5/6) and brownish yellow (10YR6/6) mottles; mediumclay; moderate medium polyhedral, parting to strong fine polyhedral structure; weak consistence moist; pH 5.4; gradual change to:
B22	60-80 cm	Yellowish brown (10YR5/4) with common (15%) strong brown (7.5YR5/6) mottles; medium heavy clay; strong medium polyhedral, parting to strong fine polyhedral structure; strong consistence, dry; some basalt fragments in patches; pH 5.5; clear change to:
B23	80+ cm	Greyish brown (2.5Y5/2) with many (20%) yellowish brown (10YR5/8) mottles; medium clay; strong fine to very fine polyhedral structure; strong consistence, dry; pH 5.7.

Key Profile Features:

Strong texture contrast between surface (A) horizon and subsoil (B21) horizon.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Strongly Acid	Low	Non-Sodic	None
Subsoil (B21 horizon)	Strongly Acid	Very Low	Non-Sodic	None
Deeper subsoil (at 80+ cm)	Moderately Acid	Very Low	Sodic	None

The surface and upper sub-soil is strongly acid. The subsoil becomes moderately acid at 80 cm depth.

The salinity rating is low-very low throughout the soil profile.

The clay content increases markedly at 45 cm depth.

Chemical and Physical Analysis:

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	Organic Carbon %	Total Nitrogen %	Exchangeable Acididty meq/100g	Exchangeable Cations				Coarse Sand (0.2-2.0 mm) %	Fine Sand (0.02-0.2 mm) %	Silt (0.002-0.02 mm) %	Clay (<0.002 mm) %	Field Capacity % w/w	Wilting Point % w/w
								Ca	Mg	K	Na
								meq/100g
A1	0-15	5.4	4.7	0.12	7.1	0.56		5.5	1	0.3	0.1	9	32	29	16	43.2	16.4
A21	15-30	5.5	4.8	0.9				1.7	1.5	0.1	0.05	9	34	32	23	30.8	10.5
A22	30-45	5.8	4.8	0.06				1.5	2.4	0.1	0.1	7	35	30	26	28.1	10.9
B21	45-60	5.4	4.8	0.11			12	2.5	7.5	0.2	0.6	3	15	15	64	45.3	27.9
B22	60-80	5.5	4.8	0.12				2.7	9.4	0.1	0.9	1	10	13	73	51	32.3
B23	80+	5.7	5.0	0.12				2.3	8	0.1	1.1	3	16	15	65	44.7	27

Profile Described By: Mark Imhof and Austin Brown (August 1998).

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