PVI7

Location: PVI Hamilton.

Australian Soil Classification: Melanic (&Ferric), Eutrophic, Brown CHROMOSOL (thick, moderately gravelly, clay loamy surface).
Northcote Factual Key: Db 2.32
Great Soil Group: Possibly brown podzolic

Geology: Tertiary/Quaternary basalt.
General Landscape Description: Near base of the slope of a low rise.
Soil Mapping Unit: Monivae gravelly loam (slope phase).

Site Description: Uncultivated area between paddocks.

PVI7 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-20 cm	Very dark greyish brown (10YR3/2); very fine sandy clay loam; moderate to strong medium polyhedral, parting to moderate to strong fine polyhedral structure; firm consistence (dry); many (30%) ferruginous nodules (2-5 mm); well structured uncultivated; pH 5.7; clear change to:	PVI7 Profile
A21	20-30 cm	Brown (10YR5/3); sporadically bleached; clay loam (very fine sandy); moderate coarse blocky, parting to moderate medium blocky structure; firm consistence (dry); pH 6.2; gradual change to:
A22	30-40 cm	Brown (10YR5/3) with few faint yellowish brown (10YR5/6) mottles; light clay (very fine sandy); strong consistence (dry); pH 6.5; clear change to:
Subsoil
B21	40-55 cm	Brown (10YR4/3) with few (10%) yellowish brown (10YR5/4) mottles; medium clay; moderate medium polyhedral, parting to moderate fine polyhedral structure; strong consistence (dry); few (5%) ferruginous nodules (2-10 mm); pH 6.5; gradual change to:
B22	55-100 cm	Brown (10YR4/3) with many (20%) brownish yellow (10YR6/6) mottles; medium clay; moderate coarse prismatic, parting to moderate to strong coarse to medium to fine polyhedral structure; few (5%) ferruginous and manganese nodules (2-10 mm); pH 6.8; gradual change to:
B23	100+ cm	Light brownish grey (2.5Y6/2) and brownish yellow (10YR6/6); medium clay; strong consistence (moist); pH 6.5.

Key Profile Features:

Strong texture contrast between surface (A) horizons and subsoil (B21) horizon.
A large amount of ferruginous nodules in the surface (A1) horizon.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface Soil (A1 horizon)	Moderately Acid	Low	Non-Sodic	None
Upper Subsoil (40 - 55 cm)	Slightly Acid	Low	Non-Sodic	None
Deep Subsoil (at 100+ cm)	Slightly Acid	Low	Sodic	None

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC 1:5	Exchangeable Cations
					Ca	Mg	K	Na
					meq/100g
A1	0-20	5.7	5.0	0.09	6.1	3.6	0.29	0.40
A21	20-30	6.2	5.3	0.06	5.3	3.5	0.12	0.44
A22	30-40	6.5	5.5	0.06	5.2	4.1	0.09	0.58
B21	40-55	6.5	5.6	0.07	6.0	6.1	0.14	0.89
B22	55-100	6.8	6.0	0.11	5.7	8.4	0.20	1.5
B23	100+	6.5	6.0	0.23	4.3	10	0.20	3.1

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	0-20	<10		37	17	6	31	22	31
A21	20-30	<10		31	14	9	31	33	31
A22	30-40			33	17	14	25	18	41
B21	40-55		11	42	25	6	17	12	61
B22	55-100		11	50	31	4	7	12	77
B23	100+

Profile Described By: Mark Imhof, Paul Rampant (January 2001).

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