SW7

Location: Terang

Australian Soil Classification: Ferric-Sodic, Eutrophic, Brown CHROMOSOL
General Landscape Description: Level volcanic plain.
Site Description:
Land Unit:
Geology: Quaternary basalt (Qvn)

SW7 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Dark brown (10YR3/3) light fine sandy clay loam; moderate medium blocky structure; very weak consistence moist; pH 5.8; clear change to:	SW7 Profile
A21	10-17 cm	Brown (10YR4/3) light fine sandy clay loam; sporadically bleached in patches; moderate medium blocky structure; very weak consistence moist; pH 5.9; abrupt change to:
A22	17-25 cm	Brown (10YR4/3) light fine sandy clay loam; very firm consistence moderately moist; contains many (50%) ferruginous concretions (2-10 mm size) pH 6.3; abrupt change to:
Subsoil
B21	25-40 cm	Dark yellowish brown (10YR4/4) with brownish yellow (10YR6/6) mottles; light medium clay (subplastic); parting to strong medium polyhedral structure; very firm consistence moderately moist; pH 6.8; clear change to:
B22	40-70 cm	Brown (10YR4/3) with brownish yellow (10YR6/6) and red (2.5YR5/8) mottles; medium clay (subplastic); weak to moderate coarse prismatic, parting to strong medium to fine polyhedral structure (smooth-faced peds); very firm consistence moderately moist; contains very few (2%) manganese flecks; pH 7.0; gradual change to:
B23	70 cm+	Brown (10YR5/3) with brownish yellow (10YR6/6) and red (2.5YR5/8) mottles; medium clay (subplastic); moderate to strong coarse prismatic, parting to strong coarse blocky structure; strong consistence moderately moist; pH 6.4.

• Strong texture contrast between surface (A) horizons (< 21% clay) and subsoil (B21) horizon (70% clay).
• Presence of an ironstone gravel ('buckshot') zone in the subsurface horizon.

The upper surface horizons are moderately acid. The upper subsoil is slightly acid to neutral. The deeper subsoil is slightly acid.	The salinity rating is very low throughout the soil profile.	The clay percentage increases abruptly at the A/B horizon boundary.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC dS/m	Organic Carbon %	Total Nitrogen %	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) %	Wilting Point % w/w
							Ca	Mg	K	Na
							meq/100g
A11	0-10	5.8	4.9	0.8	2.8	0.31	3.8	0.82	0.42	0.26	15.3	45.4	19.5	13.5	9.6
A21	10-17	5.9	5.0	0.05	1.6		3.1	0.71	0.11	0.10	15.7	47.6	20.5	13.5	6.3
A22	17-25	6.3	5.3	0.05	5.3		3.3	15	0.22	0.13	23.3	39.2	16.0	21.0	7.8
B21	25-40	6.8	5.8	0.05	3.1		6.7	6.2	0.29	0.47	7.8	15.7	4.5	70.5	26.4
B22	40-70	7.0	6.2	0.08			6.3	7.5	0.27	0.78	4.2	8.8	1.5	86.0	31.5
B23	70+	6.4	5.9	0.12			4.9	9.3	0.26	1.1	3.0	7.4	0.5	90.0	33.9

• Plant available water capacity (PAWC) is considered to be medium (estimated at 145 mm) for the top metre of this soil profile. This is based on available laboratory data. Effective PAWC is likely to be lower than this value as rooting will be restricted by the coarsely structured upper subsoil.