GP86

Location: near Lake Glenmaggie.	Australian Soil Classification: Bleached-Mottled, Magnesic, Red KUROSOL (moderate profile depth).
Geology: Ordovician sediments.	General Landscape Description: SE aspect, mid slope, hills.
Soil Mapping Unit: La Trobe	Site Description: Roadside cutting adjacent to vegetation reserve.
Native Vegetation: Stringybark trees (approx. 15 m height).

Site GP86 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-5 cm	Black (10YR2/1); loam; pH 4.5:	Site GP86 Profile
A21	5-25 cm	Brown (10YR5/3) conspicuously bleached; light sandy loam; hydrophobic; pH 5.0:
A22	25-40 cm	Yellowish brown (10YR5/4) conspicuously bleached; sandy loam; pH 5.1:
Subsoil
B21	40-60 cm	Dark red (2.5YR4/6) with reddish yellow (7.5YR6/8) and grey (10YR6/1) mottles; medium heavy clay; moderate medium to fine polyhedral structure; pH 5.1:
C	60 cm	Weathered sandstone.

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

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC 1:5	NaCl	Exchangeable Cations
						Ca	Mg	K	Na
						meq/100g
A1	0-5	4.5	3.8	0.06		1.5	0.90	0.43	0.30
A21	5-25	5.0	4.5	0.08		0.27	0.61	0.20	0.26
A22	25-40	5.1	4.6	0.09		0.10	0.90	0.250	0.31
B21	40-60	5.1	4.2	0.07		0.15	4.9	0.51	0.54

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)
A1	0-5	82	16			23	50	11	7
A21	5-25	55	5.3			20	57	14	6
A22	25-40	71	5.9			20	52	14	11
B21	40-60	300	12			14	25	9	50

• The subsoil has very low levels of exchangeable calcium compared to exchangeable magnesium (i.e. magnesic). This indicates that nutrient imbalances (e.g. calcium deficiency) may occur.
• The level of exchangeable aluminium becomes quite high in the strongly acid subsoil. This is likely to restrict the growth of aluminium-sensitive species.
• The subsoil horizons are non-sodic and well structured (parting to fine polyhedral peds). This will enhance root and water movement (apart from any chemical restrictions to plant growth).