Site MP48

Location: Murrayville Landcare Group.

Australian Soil Classification: Epibasic, Regolithic, Hypercalcic, CALCAROSOL.

Geology: Quaternary (Woorinen Formation) deposits.
General Landscape Description: Lower slope of sandy rise.
Site Description: Grazing paddock.

Soil Profile Morphology:

Surface Soil

A11	0-10 cm	Grey-brown (10YR5/3); loamy sand; weak consistence (moist); non-calcareous; pH 8.2:	Site MP48 Profile
A12	10-15 cm	Darkish greyish brown (7.5YR4/4); sandy loam (heavy); weak to firm consistence (moist); moderately calcareous; pH 8.1:
A2	15-30 cm	Greyish brown (7.5YR5/4); sandy loam (heavy); weak consistence (moist); highly calcareous; pH 8.5:
Subsoil
B21k	30-55 cm	Light brown (7.5YR7/6); fine sandy clay; weak coarse polyhedral structure; firm to very firm consistence (dry); calcareous nodules and fine-earth carbonates common (10-20%); very highly calcareous; pH 9.0:
B22k	55-90 cm	Very light greyish brown (7.5YR8/4); light clay; very firm consistence (dry); very many (50%) fine-earth carbonates; very highly calcareous; pH 9.9:
B23k	90-130 cm	Brown (7.5YR5/6); light clay; common (20%) fine-earth carbonates; very highly calcareous; pH 10.0:
B3	130+ cm	Red (2.5YR5/8) with light grey-brown (10YR7/3) mottles; clay; strong coarse blocky structure; few (5%) soft manganese segregations; moderately calcareous; pH 9.8.

Key Profile Features:

• Lack of strong texture contrast between surface (A) horizons and subsoil (B21) horizon.
• Large amounts of mainly soft carbonate (lime) in subsoil.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Moderately alkaline	low	-	None
Subsoil (B21 horizon)	Strongly alkaline	low	Non-sodic	None
Deeper subsoil (at 1.3 m)	Extremely alkaline	high	Strongly sodic	Strong

The soil profile becomes increasingly alkaline with depth.	The level of soluble salts increases with depth.
The soil profile becomes increasingly sodic with depth.	The clay content gradually increases with depth.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC 1:5	NaCl	Total Nitrogen %	Organic Carbon %	Exchangeable Cations
								Ca	Mg	K	Na
								meq/100g
A11	0-10	8.2	7.8	0.16		<0.05	0.44	4.1	1.2	0.58	0.6
A12	10-15	8.1	7.7	0.14				14	1.4	0.99	0.07
A2	15-30	8.5	8	0.14				24	2	0.97	0.07
B21k	30-55	9	8.2	0.16				24	6.7	0.5	0.43
B22k	55-80	9.9	8.7	0.34	<0.01			6.6	7.8	0.8	1.1
B23	80-130	10	8.7	0.52	<0.01
B3	130+	9.8	8.9	0.62	0.01			2.3	4.7	0.8	4.2

Horizon	Horizon Depth (cm)	Exchangeable Aluminium mg/kg	Coarse Sand (0.2-2.0 mm)	Fine Sand (0.02-0.2 mm)	Silt (0.002-0.02 mm)	Clay (<0.002 mm)
A11	0-10		38	54	8	1
A12	10-15		34	52	11	1
A2	15-30		29	49	12	7
B21k	30-55		20	32	17	26
B22k	55-80	<5	17	20	22	36
B23	80-130
B3	130+	<5

Management Considerations

Whole Profile

• In general, management strategies for all soils should aim to: increase organic matter levels in the surface soil, minimise the degradation of soil aggregates and porosity, promote the development of stable biopores, break up any hardpans, and improve the calcium status of the ion exchange complex. Particularly when sodium plays a significant part i.e. the soil is sodic. Less frequent tillage, using less aggressive implements, and working the soil at optimum moisture conditions can all assist in maintaining soil aggregation and porosity, as well as reducing the breakdown of organic matter. Farming practices on cropping soils such as residue retention, minimum tillage and pasture rotations could be utilised to build up organic matter, reduce erosion risk and increase the soils low inherent fertility.
• The soil profile is strongly to extremely alkaline throughout. This suggests that phosphorus and some trace elements such as iron, manganese, zinc and copper may be poorly available to plants and deficiencies may occur.
• Boron toxicity can also occur in strongly alkaline soils.

Profile Described By: Mark Imhof, (31/8/99).

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