Site MP27

Location: Woomelang

Australian Soil Classification: Calcic, Mottled-Subnatric, Brown SODOSOL

General Landscape Description: Gently undulating plain within the Hopetoun Land System (Rowan and Downes, 1963).

Site MP27 Landscape.

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Dark brown (7.5YR4/4); sandy clay loam; hardsetting and massive; firm to very firm consistence dry; pH 8.7; sharp change to:	Site MP27 Profile
Subsoil
B21	10-30 cm	Strong brown (7.5YR4/6) with yellowish red (5YR5/8) mottles; medium clay; moderate blocky structure; firm consistence slightly moist; pH 9.3; gradual change to:
B22k	30-80 cm	Yellowish red (5YR5/8) with reddish yellow (7.5YR6/6) mottles; medium clay; moderate blocky structure; weak consistence, moderately moist; fine earth carbonates common (10%); pH 9.9; gradual change to:
B31	80-130 cm	Yellowish red (5YR5/8) with reddish yellow (7.5YR6/6) mottles; medium clay; moderate blocky structure; weak consistence, moderately moist; fine earth carbonates common (10%); pH 9.9; gradual change to:

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	strongly alkaline	very low	sodic	none
Subsoil (B21 horizon)	very strongly alkaline	low	sodic	none1
Deeper subsoil (at 1 m)	very strongly alkaline	high	very strongly sodic	none2

¹ Strong dispersion after remoulding. ² Lack of dispersion due to high levels of soluble salts.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC 1:5	NaCI %	Exchangeable Cations				Field Capacity pF 2.5	Wilting Point pF 4.2	Coarse Sand (0.2 - 2.0 mm)	Fine Sand (0.02 -0.2 mm)	Silt (0.002 -0.02 mm)	Clay (<0.002mm)
						Ca	Mg	K	Na
						meq/100g
A1	0-10	8.7	7.9	0.12		10.4	2.3	1.4	0.2	7	23	34	34	2	23
B21	10-30	9.3	9.2	0.24		10.5	9.4	1	2.6	11	38	24	17	3	43
B22k	30-80	9.9	9	0.86	0.07	2.3	9.3	1.2	10.8	46	40
B31	80-130	9.5	8.7	1.44	0.23	3.2	8.8	1.3	10.5	44	37

Management Considerations:

Surface (A) Horizons

• The surface soil is strongly alkaline which indicates that phosphorus and some trace elements (e.g. iron, manganese, boron, copper and zinc) may be poorly available to plants. Deficiencies should be determined by plant tissue analysis.
  
  
• The surface soil is hardsetting and organic matter is important for maintaining soil aggregation.

Subsoil (B) Horizons

• The subsoil is very strongly alkaline which indicates that phosphorus and some trace elements (e.g. iron, manganese, boron, copper and zinc) may be poorly available to plants.
  
  
• The subsoil from 30 cm depth is strongly sodic and has a low exchangeable calcium:magnesium ratio. This will adversely affect soil structure and result in restricted root and water movement through the profile.
  
  
• The level of soluble salts increases with depth in the subsoil and is high in the deeper subsoil (from 80 cm depth). These levels will restrict the growth of deeper-rooted salt sensitive species.

Profile Described By: Mark Imhof and John Martin (24/1/93).

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