Site WW15

Location: Lillimur South

Australian Soil Classification: Hypercalcic, mottled-Subnatric, Brown SODOSOL
Northcote Factual Key: Dy5.43
Great Soil Group: solodic

Site WW15 Landscape

General Landscape Description: Mid-slope on gently undulating plain. The landscapes in these units consist of gently undulating plains and gently undulating rises (closer spaced undulations). Ferric Sodosols may also occur in association with this soil type, particularly north of Apsley where this site is located.

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Very dark greyish brown (10YR3/2) loamy sand; weakly structured; firm consistence when dry; pH 7.8; abrupt transition to:	Site WW15 Profile
A2	10-35 cm	Light brown (7.5YR6/4) sand; conspicuously bleached when dry; structureless; very firm consistence when dry; a few ferruginised iron nodules; pH 8.4; sharp transition to:
Subsoil
B21	35-75 cm	Yellowish brown (10YR5/4) light medium clay; many coarse distinct red mottles; strong prismatic structure (peds >200 mm) parting to prismatic and blocky structure (peds 20-50 mm), parting to moderate blocky structure (10-20 mm); dark organic staining on the faces of the prisms; strong consistence when dry; dispersive when worked; pH 5.8; clear transition to:
B22	75-100 cm	Light grey (2.5Y7/2) light medium clay (fine sandy); with yellowish red mottles; same structure as horizon above; very firm consistence when slightly moist; dispersive when worked; pH 7.3; clear transition to:
B23k	100-130 cm	Light grey (2.5Y7/2) sandy clay; with strong brown mottles; very firm consistence when moderately moist; soft (and a few hard) calcium carbonate segregations are abundant (50%); pH 8.9:
B3	130-180 cm	Light grey (2.5Y7/2) sandy clay (becoming light sandy clay loam at depth); with yellow mottles; structureless; firm consistence when moderately moist; pH 9.0:
BC	180-200 cm +	Loamy sand; structureless; weak consistence when moderately moist; pH 8.8.

Soil Profile Characteristics:

Horizon	pH	Salinity	Sodicity	Dispersion	Internal Drainage	Hydro-phobicity
Surface (A1 horizon)	slightly alkaline	low	non-sodic	-	-	moderate
Subsoil (B21 horizon)	moderately acid	low	sodic	nil¹	Imperfectly drained²	-
Deeper subsoil (at 1 metre)	strongly alkaline	low-medium	sodic	nil¹	-	-

¹ Strongly to complete dispersion after remoulding.
² Most impeding horizon of the profile that will affect plant growth.

Site 15 Graph

Key Profile Features:

Sandy surface soil.
Hydrophobic surface soil.
Bleached A2 horizon.
Strong texture contrast between surface soil and subsoil.
Top of the subsoil (B21) is acidic.
Sodic subsoil.
Prismatic structure.
Mottled subsoil.
Dispersive subsoil following cultivation when wet.
Weathered sandstone occurs at 2m depth.

Soil Restrictions and Management Prescriptions:

Feature	Result	Management Prescription
Sandy surface soil.	Poor plant available water holding capacity. Poor nutrient holding capacity. Increased risk of wind erosion. Potential for hydrophobicity.	Dryland cropping. Minimum tillage and stubble retention, improve organic matter through maintenance of vegetative cover and growing green manure crops. Establish wind protection barriers. Horticulture. Improve organic matter through maintenance of vegetative cover and growing green manure crops. Establish wind protection barriers. Increase frequency of fertiliser (eg side dressings) and irrigations.
Hydrophobic surface soil.	Poor infiltration of water into the soil. Increased risk of water erosion. Poor seed germination.	Maintenance of surface vegetative cover. Claying (application of subsoil clay from other areas directly to the soil surface).
Bleached A2 horizon.	Indication of waterlogged conditions (impeded internal drainage) within the surface soil. Poor soil structure (often massive). Low organic matter, water holding capacity and nutrition within the horizon.	Dryland cropping. Include deep rooted crops in the rotation, minimum tillage and stubble retention. Apply gypsum if the surface soil is responsive to gypsum. Optimise plant growth through a regular and balanced fertiliser programme. Horticulture. Improve organic matter through maintaining optimum plant growth and growing green manure crops between the rows. Minimum tillage and surface vegetative cover. Apply gypsum if the surface soil is responsive to gypsym. Optimise plant growth through a regular and balanced fertiliser programme. Install subsoil drainage (if appropriate).
Strong textural contrast between surface soil and subsoil (duplex).	Strong texture and structure difference between the surface soil and the subsoil can result in impeded internal drainage and restricted root growth.	Improve organic matter through maintenance of vegetative cover and growing green manure crops. Reduce tillage. Mounding for orchards. Optimise plant growth through regular balanced fertiliser programme. Consider sub-surface drainage (if appropriate).
Acidic upper subsoil.	Potential nutrient imbalance. Unsuitable for acid intolerant plants.	Grow acid tolerant species or varieties.
Sodic clay subsoil.	Poor water and air movement into the subsoil resulting in waterlogging (impeded internal drainage). Poor root growth into the subsoil reducing the volume of the soil able to be exploited.	Gypsum applications if the subsoil is close to the surface and surface soil textures are light. Dryland cropping. Include deep rooted crops in the rotation, minimum tillage and stubble retention. Horticulture. Deep ripping with gypsum, install tile drainage (if appropriate).
Columnar or prismatic subsoil structure.	Often indicates sodic clay subsoil. Poor water and air movement into the subsoil resulting in waterlogging (impeded internal drainage). Poor root growth into the subsoil reducing the volume of the soil able to be exploited. Very difficult to cultivate particularly if surface soil is shallow.	Apply gypsum if the subsoil is close to the surface and surface soil textures are light. Dryland cropping. Include deep rooted crops in the rotation, minimum tillage and stubble retention. Horticulture. Deep ripping with gypsum, install tile drainage (if appropriate). These soil are difficult to manage, not suitable for high levels of production unless substantial modification can be achieved.
Mottled subsoil.	Indication of periodic waterlogging, particularly if grey and yellow mottles predominate.	Consider sub-surface drainage (if appropriate). Apply gypsum if subsoil is sodic and close to the surface.
Dispersion when reworked.	Indication of soil sodicity. Soil structure collapses following tillage and wetting resulting in poor soil structure that reduces water movement and plant root growth. Increases water erosion hazard.	Do not cultivate wet soil (cultivate when moist). Apply gypsum if growing high value crops.

Land Suitability Rating Table:

LAND USE	SUITABILITY CLASS	MAJOR LIMITING COMPONENT
Wheat	2	Climate, landscape, soil
Canola	2	Climate, landscape, soil
Chickpeas	3	Soil
Lentils	3	Soil
White clover seed	2	Landscape, soil
Lucerne for seed production	3	Soil
Viticulture	3	Soil
Apples	2	Climate, soil
Potatoes	3	Soil
Carrots	3	Soil
Onions	3	Soil
Sweet corn	3	Soil
Radiata Pine	3	Climate
Blue Gum	3	Climate

Land Suitability Assessment and Primary Limitations:

Wheat	Climate	2	Moderate frost risk, slightly high rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	2	Slightly impeded internal drainage, hydrophobicity.
Canola	Climate	2	Moderate frost risk.
	Landscape	2	Wind erosion hazard.
	Soil	2	Slightly impeded internal drainage, hydrophobicity, slightly acid subsoil pH
Chickpeas	Climate	2*	Moderate frost risk, moderate to high rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	3	Sandy surface soil, impeded internal drainage.
Lentils	Climate	2	Moderate frost risk, slightly high rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	3	Sandy surface soil, impeded internal drainage.
White clover seed	Climate	1	No major limitation.
	Landscape	2	Wind erosion hazard.
	Soil	2	Sandy surface soil texture, soil salinity, slightly impeded internal drainage, hydrophobicity.
Lucerne for seed production	Climate	1	No major limitation.
	Landscape	2	Wind erosion hazard.
	Soil	3	Impeded internal drainage.
Viticulture	Climate	2	Moderate frost risk.
	Landscape	1	No major limitation.
	Soil	3	Impeded internal drainage.
Apples	Climate	2	Moderate frost risk, slightly high mean maximum January temperature.
	Landscape	1	No major limitation.
	Soil	2	Slightly alkaline surface soil pH, slightly acidic subsoil, soil salinity, slightly impeded internal drainage, hydrophobicity.
Potatoes	Climate	2	Slightly high mean maximum January temperature.
	Landscape	2	Wind erosion hazard.
	Soil	3	Impeded internal drainage.
Carrots	Climate	1	No major limitation.
	Landscape	2	Wind erosion hazard.
	Soil	3	Impeded internal drainage.
Onions	Climate	2	Moderate frost risk.
	Landscape	2	Wind erosion hazard.
	Soil	3	Impeded internal drainage.
Sweet corn	Climate	2	Slightly low mean monthly temperature (October - March).
	Landscape	2	Wind erosion hazard.
	Soil	3	Sandy surface soil texture.
Radiata Pine	Climate	3	Low rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	2	Slightly alkaline subsoil pH, slightly impeded internal drainage, hydrophobicity.
Blue Gum	Climate	3	Low rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	2	Slightly alkaline subsoil pH, slightly impeded internal drainage, hydrophobicity.

* Some areas may have higher rainfall.

Profile Described By: Mark Imhof, Nathalie Baxter (09/01/97).

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