SW73

Location: Tulloh

Australian Soil Classification: Bleached-Mottled, Mesotrophic, Brown CHROMOSOL

General Landscape Description: Undulating low hills.
Site Description: Waxing upper slope (10%), eastern aspect.
Geology: Ambiguous: Either Dilwyn (Colac 1:250 000) or Eastern View Formation (Colac 1:50 000).

SW73 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-20* cm	Dark brown (10YR3/3 moist), fine sandy loam; weakly pedal; weak consistence dry; pH 5.4:	SW73 Profile. Note: Surface (A1) horizon has been stripped from the soil profile
A2	20*-40 cm	Dark greyish brown (10YR4/2 moist), pale brown (10YR6/3 dry); conspicuously bleached; sandy loam; apedal, massive; very firm consistence dry; (minor <5%), fine (5-15 mm), irregular rounded ferruginised sandstone gravel; pH 5.6; abrupt to clear and wavy change to:
Subsoil
B21t	40-70 cm	Dark yellowish brown (10YR4/5 dry); with prominent (5-15 mm), red (10R4/8 moist) to dark red (2.5YR4/8 moist) to yellowish brown (10YR6/8 moist) mottles in ped interiors, reddest in ped centres; medium clay; coarse prismatic structure; pH 5.8; strong consistence (dry); gradual change to:
B22t	70/80-100/110 cm	Dark yellowish brown (10YR4/5 moist and dry) with prominent (5-15 mm), red (10R4/8 moist) to dark red (2.5YR4/8 moist) to yellowish brown (10YR6/8 moist) mottles in ped interiors (reddest away from ped face); medium clay; white (2.5Y8/1) clay adjacent to cutans; pH 6; gradual change to:
B/C	100/110 cm+	Weak red to dusky red (10R5/3-3/2); ferruginised sandstone with yellowish and white edges; clay infill and weathering in joints; pH 6.0.

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

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Strongly Acid	Low - Moderate	Non-Sodic	None
Subsoil (B21 horizon)	Moderately Acid	Very Low	Non-Sodic	None
Deeper subsoil (at 100+ cm)	Moderately Acid	Very Low	Non-Sodic	None

The surface soil is strongly acid. The subsoil is moderately acid.

Salinity rating is low to moderate in the surface becoming very low in the subsoil.

The soil is non sodic throughout.

The clay content increases markedly at the A/B boundary.

Horizon	Sample Depth (cm)	pH (water)	pH (CaCl2)	EC 1:5	Nitrogen %	Organic Carbon %	Exchangeable Cations
							Ca	Mg	K	Na
							meq/100g
A1	0-20*	5.4	4.8	0.17	0.35	4.3	5.2	1.1	0.49	0.32
A2	20*-40	5.6	4.9	0.1			0.62	0.91	0.07	0.1
B21	40-70	5.8	5.2	0.11			1.9	7.4	0.1	0.53
B22	70-105	6	5.2	0.06			1.5	6.4	0.07	0.4
BC	105+	6	5.2	<0.05

Horizon	Sample Depth (cm)	Exchangeable Aluminium mg/kg	Exchangeable Acidity meq/100g	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	0-20*	17	15	26.5	10.2	24	38	12	13
A2	20*-40	<10	4.8	14.6	4.2	25	46	22	6
B21	40-70	<10	9.4	42.4	27.6	9	11	8	74
B22	70-105	<10	7.9	36	23.6	16	12	7	63
BC	105+

Management Considerations:

Notes

• Similar pattern on both sides of unnamed creek. Soils increasingly vertic downslope, gleying increases, A2 thickens. Colluvial derived from and lying on Tad or Tae2. Becoming quite pallid in places below colluvial mass. Fragments are angular, occasional weakly rounded and up to 200 mm diameter at largest, generally ~100 mm.