Site WW13

Location: Lillimur

Australian Soil Classification: Calcic, Mottled-Mesonatric, Grey SODOSOL
Northcote Factual Key: Dg4.43
Great Soil Group: solodised solonetz

General Landscape Description: This soil occurs on the mid to lower slope of the gently undulating plains, gently undulating plains (closer spaced undulations) and undulating rises (closer spaced undulations) land units of the Yellow Gum Plains and Rises group. This soil is similar to WW12 that has been used to represent these land units. This site is located on a roadside reserve area, hence the organic accumulation at the soil surface.

Site WW13 Landscape

Soil Profile Morphology:

Surface Soil

AO	0-3 cm	Organic layer:	Site WW13 Profile
A1	3-10 cm	Brown (7.5YR4/2) loamy sand; weakly structured; pH 6.6:
A2	10-20 cm	Pink (7.5YR7/4) sand; structureless; pH 6.3:
Subsoil
B21	20-40 cm	Very pale brown (10YR7/3) medium heavy clay; many distinct brownish yellow mottles; coarse columnar structure (peds >200 mm), parting to strong polyhedral structure (peds 10-20 mm) and moderate polyhedral structure (peds 5-10 mm); clay skins; dispersive when worked; pH 5.8:
B22	40-70 cm	Brownish yellow (10YR6/8) sandy clay; completely dispersive; pH 7.2:
B23	70-90 cm	Pale yellow (2.5Y7/4) medium heavy clay (sandy); a few faint brownish yellow mottles; moderate prismatic structure (peds 20-100 mm), parting to strong blocky structure (peds 20-50 mm); a few manganese flecks; completely dispersive; pH 8.5:
B24k	90-150 cm	Light grey (2.5Y7/2) medium heavy clay (sandy); moderate prismatic structure (peds 50-100 mm), parting to strong blocky structure (peds 20-50 mm); soft calcium carbonate segregations are common, with a few hard calcium carbonate nodules occurring in patches; pH 9.6:
B25	150-200 cm+	Light grey (2.5Y7/2) medium clay (sandy); moderate polyhedral structure (peds 20-50 mm), parting to strong polyhedral structure (peds 10-20mm); pH 9.0.

Soil Profile Characteristics:

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

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

Key Profile Features:

Sandy surface soil.
Hydrophobic surface soil.
Strong textural contrast between surface soil and subsoil.
Bleached A2 capping over large hardsetting clay columns.
Acidic surface soil.
Top of the subsoil is dispersive following cultivation when wet.
Clay skins on the B21 horizon repel water.
Sodic subsoil.
Columnar structure.
Subsoil mottling.
Alkaline subsoil.

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).
Acidic surface soil.	Potential nutrient imbalance. Unsuitable for acid intolerant plants.	Apply lime.
Bleached A2 horizon.	Indication of waterlogged condition (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 resposive 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 gypsum. 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).
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 if subsoil is not to deep. 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 if subsoil not to deep. Install tile drainage (if appropriate). These soil are difficult to manage and are not suitable for high levels of production unless substantial modifications 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.
Alkaline subsoil.	Potential nutrient imbalance. Unsuitable for alkaline intolerant plants. May indicate subsoil sodicity.	Grow alkaline tolerant plants.

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	Depth of surface soil, slightly acidic pH, soil salinity, slightly impeded internal drainage, hydrophobicity.
Potatoes	Climate	2	Slightly high mean maximum January temperature.
	Landscape	2	Wind erosion hazard.
	Soil	3	Shallow depth of surface soil, impeded internal drainage.
Carrots	Climate	1	No major limitation.
	Landscape	2	Wind erosion hazard.
	Soil	3	Shallow depth of surface soil, impeded internal drainage, soil salinity.
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	Shallow depth of surface soil, impeded internal drainage.
Radiata Pine	Climate	3	Low rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	2	Slightly impeded internal drainage, hydrophobicity.
Blue Gum	Climate	3	Low rainfall.
	Landscape	2	Wind erosion hazard.
	Soil	2	Slightly impeded internal drainage, hydrophobicity.

* Some areas may be higher rainfall.

Profile Described By: Mark Imhof, Nathalie Baxter (08/01/97).

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