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Site LS1

Location: Kinimakatka

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

Northcote Factual Key: Dr 3.23
Great Soil Group: red-brown earth (sodic)

General Landscape Description: Upper slope on the eastern side of a north-south trending gently undulating rise.

LS1 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Dark brown (7.5YR3/4); sandy clay loam; weakly structured; weak consistence dry; pH 6.0:	LS1 Profile
A2	10-15 cm	Brown (7.5YR4/4); sandy clay loam; weakly structured but tends to fracture into platy like fragments; very strong consistence dry (possible cultivation pan); pH 6.5; sharp boundary change to:
Subsoil
B21	15-25 cm	Reddish brown (5YR4/4) and dark reddish grey (5YR4/2); heavy clay; strong very coarse prismatic structure; very strong consistence dry; pH 7.3:
B22	25-60 cm	Yellowish red (5YR5/8) with dark reddish grey (5YR4/2) mottles; heavy clay; strong very coarse prismatic, parting to moderate blocky structure; pH 9.2:
B23	60-100 cm	Yellowish brown (10YR5/4) with slight red mottles; medium heavy clay; moderate medium prismatic (finer than above) parting to moderate medium blocky structure; contains a common (10 - 20%) amount of soft and nodular carbonate in pockets and very few (2 %) ironstone nodules; pH 9.4.

Key Profile Features:

• Strong texture contrast between surface (A) horizons and heavy clay (B) horizons.

Soil Profile Characteristics:

-	pH	Salinity	Sodicity	Dispersion
Surface (A1 horizon)	Moderately Acid	Very low	Non-Sodic	None
Subsoil (B21 horizon)	Slightly Alkaline	Very low	Sodic	Slight
Deeper Subsoil (at 1 metre)	Very Strongly Alkaline	High	Strongly Sodic	Moderate- Strong

The surface soil is moderately acid. The subsoil is slightly alkaline becoming very strongly alkaline with depth.

The salinity rating is very low in the surface and upper subsoil becoming high with depth.

The surface is non-sodic. The subsoil is sodic becoming strongly sodic with depth..

Management Considerations:

Surface (A) Horizons

• The surface soil does not slake or disperse when immersed in water. This is a favourable condition which can be preserved by maintaining organic matter levels which assists in reducing slaking.
• The surface horizon has a moderate nutrient status and adequate organic carbon and nitrogen levels.
• The subsurface (A2) horizon may be prone to developing a cultivation pan which will inhibit root growth and restrict water movement. This could develop if the soil is cultivated in a moist condition (as indicated by dispersion of the A2 horizon that occurs after remoulding).

Subsoil (B) Horizons

• The top of the subsoil is sodic and slightly dispersive which may limit water and root movement down the profile. The deeper subsoil becomes increasingly sodic and dispersive. The addition of gypsum with deep ripping has been advocated by some researchers as an ameliorative technique for sodic subsoils. A test strip could be used to assess likely benefits.
  
  

Comments from Landholder:

• Gypsum used successfully.
• Wheat/chickpea/pasture rotation used.
• Good wheat yields achieved.
• Superphosphate applied.

Other Comments:

• Gypsum application together with ripping to approximately 20 - 25 cm depth has been beneficial on similar soils at Winiam.

Profile Described By: Mark Imhof, David Rees, John Martin, Sonia Thompson (May 1994).