PVI 6

Site: PVI 6	Land Unit: Monivae Basalt
*Aust. Soil Class.:* Ferric-Sodic, Mesotrophic, Brown CHROMOSOL (thick, clay loamy surface - moderate profile depth) (confidence level 1)

General Land Unit Description:
The level to gently undulating basalt plains between Branxholm and Glenthompson consist of an association of Vertic or Ferric Brown Chromosols and Ferric Brown Sodosols. The Chromosols typically occur on the upper slopes and crests of very slight rises that may have scattered surface boulders, and Sodosols on the lower slopes and depressions. Sodosols or Vertosols, occasionally with a sporadic bleached subsurface horizon, are usually found in open depressions or drainage lines.

Site Description:

Geology: Quaternary basalt	Landform pattern: Level to gently undulating plain
Position in landscape: Low lying area below rise	Internal drainage: Moderately well drained

Soil Profile Morphology

A1	0-20 cm	Very dark greyish brown (10YR3/2), fine sandy clay loam, weak coarse blocky, weak consistence (dry), rusty root channel mottles, pH 5.3. Clear change to:
A2	20-35 cm	Brown (10YR5/3), clay loam (fine sandy), firm consistence (dry), very many (60%) ferruginous nodules (2-12 mm), few (10%) basalt fragments (5-12 mm), pH 5.8. Abrupt change to:
	Subsoil
B21	35-50 cm	Brown (10YR4/3) with few (5%) faint dark yellowish brown (10YR4/6) mottles, light medium clay, strong coarse blocky, parting to strong medium to fine polyhedral structure, strong consistence (dry), pH 5.6. Clear change to:
B22	50-70 cm	Dark greyish brown (10YR4/2) with yellowish brown (10YR5/6) and strong brown (7.5YR4/8) mottles, medium heavy clay, strong coarse blocky, parting to strong medium to fine polyhedral structure, very firm consistence (dry), pH 5.8. Gradual change to:
B23	70-90 cm	Dark grey (10YR4/1) with yellowish brown (10YR5/8) and strong brown (7.5YR5/6) mottles, medium heavy clay, strong coarse to medium blocky structure, strong consistence (dry), pH 6.2. Gradual change to:
C	90+ cm	Weathered basalt.

Key Profile Features

Strong texture contrast between surface (A) horizons and subsoil (B21) horizon
Large amount of ferruginous nodules in subsurface (A2) horizon

Soil Profile Characteristics

	pH	Salinity Rating	Sodicity	Dispersion
Surface soil (A1 horizon)	Strongly Acid	Low	Non-Sodic	None
Upper subsoil (35-50 cm)	Moderately Acid	Low	Non-Sodic	None
Deeper subsoil (at 70-90 cm)	Slightly Acid	Low	Sodic	None

Horizon	Horizon Depth	pH (water)	pH CaCl2	EC dS/m	NaCl %	Exchangeable Cations				Ex Al mg/kg	Ex Ac meq/100g	Field pF2.5	Wilting Point pF4.2	Coarse Sand (0.02-0.2mm)	Fine Sand (0.02-0.2mm)	Silt (0.02-0.02mm)	Clay (<0.002mm)
						Ca	Mg	K	Na
						meq/100g
A1	0-20	5.3	4.6	0.07		4.3	1.47	0.11	0.18	16		39.1	20.4	11.1	33.7	25.0	22.5
A2	20-35	5.8	5.0	0.07		2.9	2.4	0.11	0.31	<16		26.9	11.6	21.9	25.1	20.0	27.5
B21	35-50	5.6	4.6	0.07		3.0	6.1	0.15	0.87	32	11	41.0	26.3	2.0	14.2	11.0	68.5
B22	50-70	5.8	4.8	0.10		2.7	7.9	0.15	1.5	21	15	46.6	31.3	1.0	5.4	7.5	83.0
B23	70-90	6.2	5.5	0.12		3.0	8.9	0.17	2.2	<10		49.9	30.7	2	6.1	9.5	80

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