Site MP49

Location: Murrayville Landcare Group.

Australian Soil Classification: Epibasic, Petrocalcic, Lithocalcic, CALCAROSOL.

General Landscape Description: Low rise on a gently undulating plain.
Geology: Quaternary (Woorinen Formation) deposits.

Soil Profile Morphology:

Surface Soil

A11	0-10 cm	Dark greyish brown (7.5YR3/4); sandy loam; non-calcareous; pH 7.8:	Site MP49 Profile
A12	10-20 cm	Reddish brown (5YR5/8); sandy clay loam; very firm consistence (dry); contains many (40%) calcrete fragments; moderately calcareous; pH 8.2:
Subsoil
C	20-45 cm	Calcrete Layer:
2B21	45-70 cm	Lightish red-brown (2.5YR5/8); light clay (fine sandy); contains many (50%) soft calcareous segregations with calcareous fragments are common (20%); highly calcareous; pH 9.6:
2B22	70-100 cm	Light medium clay (sandy); soft calcareous segregations are common (20%); highly calcareous; pH 9.8:
2B23	100+ cm	Medium clay (fine sandy); contains a few (2-5%) soft manganiferous segregations; moderately calcareous; pH 9.4.

Key Profile Features:

• Medium depth of surface soil overlying calcrete.
• Presence of thick calcrete layer below surface soil.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A11 horizon)	Slightly alkaline	Low	Non-sodic	None
Sub-surface (A12 horizon)	Moderately alkaline	Low	Non-sodic	None1
Deeper Subsoil (at 0.45 m)	Very strongly alkaline	Very high	Sodic	None2

¹Moderate dispersion after remoulding. ²Slight dispersion after remoulding.

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	7.8	7.1	0.19		0.12	1.5	6.5	2.1	1.4	0.09
A12	10-20	8.2	7.6	0.17				11	3.5	1	0.19
2B21	45-70	9.6	8.9	1.1	0.2			5.6	8.3	0.7	2.1
2B22	70-100	9.8	9	0.97	0.18
2B23	100+	9.4	8.6	1.4	0.28			1.1	11	1.8	5.1

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)
A11	0-10			11	5	39	45	4	12
A12	10-20			14	6	34	42	5	18
2B21	45-70	<5				20	28	7	13
2B22	70-100								-
2B23	100+	<5				20	38	13	27

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.
• The soil profile will be well drained. Water is likely to move rapidly through the fractured calcrete layer.
• Plant available water capacity will be restricted by the shallow depth of soil above the calcrete layer.
  

Surface (A) Horizons

• The subsurface (A12) horizon disperses moderately after remoulding. Disturbance to this horizon by tillage when in a moist to wet condition, may result in some structural degradation.

Subsoil (B) Horizons

• The calcrete layer will restrict root and water movement.
• The soil below the calcrete layer is also likely to restrict plant root growth. It is sodic, has a very high level of soluble salts and is very strongly alkaline.

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

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