SFS16

Location: Hamilton

Australian Soil Classification: Haplic, Self-Mulching, Black VERTOSOL

Northcote Factual Key: Ug 5.16
Great Soil Group: Possibly Wiesenboden.
Soil Mapping Unit: Buckley Clay (Newell A).

General Land Unit Description: This land unit consists of the smaller swamps and depressions which occur on the basalt plains.

Landscape Description: Level Plain
Site Description: Drainage depression (part of a former drained swamp).
Geology: Alluvium overlying Tertiary/ Quaternary basalt Newer Volcanics.

SFS16 Landscape

Soil Profile Morphology:

Surface Soil

Ap	0-20 cm	Very dark grey (10YR3/1); medium heavy clay; self mulching surface condition; strong fine to moderate polyhedral structure; pH 6.0; clear change to:	SFS16 Profile
Subsoil
B21t	20-60/70 cm	Very dark grey (10YR3/1); heavy clay; strong coarse prismatic structure; slickensides at ped bases; pH 6.6; clear change to:
B22ss	60/70-100/110 cm	Grey (5Y5/1) with common (20%) fine to medium yellowish brown (10YR5/6) mottles; heavy clay; prominent slickensides becoming larger (>30 cm) at depth; pH 7.5; gradual change to:
B23ss	110+ cm	Pale olive (5Y6/4) with common fine yellowish brown (10YR5/6) mottles; heavy clay; prominent slickensides; pH 7.6.
		Subsoil Ped

Key Profile Features:

Clay texture throughout soil profile
Significant cracking when profile is dry.
Prominent slickensides in subsoil.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Moderately Acid	Low	Non Sodic	None
Subsoil (B21 horizon)	Slightly Acid	Very Low	Non Sodic	None¹
Deeper Subsoil (at 130+ cm)	Slightly Alkaline	Moderate	Sodic	None¹

¹ Moderate dispersion after remoulding.

Image: SFS16 graphs

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC 1:5	NaCI %	Organic Carbon %	Nitrogen %	Exchangeable Cations
								Ca	Mg	K	Na
								meq/100g
Ap	0-10	6.0	5.3	0.23		3.1	0.29	16	18	0.68	1.5
B21	10-50	6.6	5.6	0.16				15	21	0.84	2.2
B22	50-90	7.5	6.8	0.41	0.07			15	26	0.7	4.4
B23	90-130	7.6	7.1	0.81	0.14			13	25	0.9	4.8

Horizon	Horizon 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)


Ap	0-10	11	21	56	36	2	10	14	63
B21	10-50		16	59	33	1	9	18	67
B22	50-90			58	40	1	8	12	75
B23	90-130					1	7	10	74

Management Considerations:

Whole Profile

Plant available water capacity (PAWC) is considered to be high (estimated at 167 mm) in the upper 100 cm of this soil profile.

NOTES:
Grey Vertosols tend to dominate the smaller swamps and depressions on the plains. On the other hand, Black Vertosols are commonly found in the swamps and depressions associated with the stony rise landscapes and the larger alluvial plains. Both soil types are typically sodic at depth and imperfectly drained. There are minor occurrences of Sodosols. In some areas of the basalt plain, this land unit would have been incorporated into the basalt land units.

Profile Described By: Richard MacEwan (December 1999).

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