Soil/Landform Unit 135

Gentle plain and associated drainage depression of the undulating rises beside the Princes Highway at Pettavel. These rises overlook Geelong and have become populat for residential development purposes

Area:

1051 ha

0.08% of CMA region

The undulating basalt rises in the Mount Duneed area are very similar to many of the plains and associated rises with deep

regolith

profiles across the Western Plains. This area originally carried woodland with

Eucalyptus viminalis

and

E. ovata

that are now only found as roadside remnants. The only significant vegetation community today is the plains grasslands (2%). The gentle to undulating rises have mainly been used for grazing, however of recent times horticulture and viticulture, in particular, have been observed on these basalt rises. Alkaline

mottled

yellow texture contrast soils are common across all landscape elements, with better drained and higher fertility soils located at the footslopes of Mount Duneed. Having a moderate nutrient holding capacity and water holding capacity, minor gully erosion can occur where topsoils are removed and

sodic

subsoils exposed.

Vines on slopes of undulating rises at Pettavel
	Pettavel winery and restaurant, an example of developing viticulture in the region

Component	1	2	3	4
Proportion of soil-landform unit	12%	65%	20%	3%
CLIMATE Rainfall (mm)	Annual: 640
Temperature (^oC)	Minimum 10, Maximum 19
Precipitation less than potential evapotranspiration	October-April
GEOLOGY Age and lithology	Quaternary basalt, Cretaceous fluvio-volcanic sandstone and conglomerate
Geomorphology	6.1.4 Volcanic Western Plains with well developed drainage
LANDUSE	Uncleared: Nature conservation Cleared: Sheep and beef cattle grazing; cropping; residential development; viticulture; horticulture
TOPOGRAPHY Landscape	Undulating basalt rises
Elevation range (m)	40-141
Local relief (m)	30
Drainage pattern	Dendritic
Drainage density (km/km²)	0.9
Landform	Gentle rise			Drainage lines
Landform element	Broad low crest	Upper and mid slopes	Lower slope
2 (1-4)Slope and range (%)	3 (1-7)	2 (0-3)	3 (0-5)
Slope shape	Convex	Convex	Linear	Concave
NATIVE VEGETATION Ecological Vegetation Class	Plains Grassland (2%)
SOIL Parent material	In situ basalt	In situ basalt and colluvium	In situ basalt and colluvium	Colluvium and alluvium
Description (Corangamite Soil Group)	Alkaline mottled brown, grey or yellow texture contrast soils (36)	Alkaline mottled brown, grey or yellow texture contrast soils (36)	Alkaline mottled brown, grey or yellow texture contrast soils (36)	Alkaline mottled brown, grey or yellow texture contrast soils (36)
Soil type sites	SFS6, CLRA47, MM5015	SFS6, CLRA47, MM5015	SFS6, CLRA47, MM5015	SFS6, CLRA47, MM5015
Surface texture	Fine sandy clay loam	Fine sandy clay loam	Fine sandy clay loam	Fine sandy clay loam
Permeability	Low to moderate	Low to moderate	Low	Very low
Depth (m)	<2	<2	<2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Texture contrast, moderate nutrient holding capacity and water holding capacity (available water capacity) in upper soil. Heavy, often expansive clay subsoil. Soil depth from shallow (low available water capacity) to deep.	Texture contrast, moderate nurient holding capacity and water holding capacity (available water capacity) in upper soil. Heavy, often expansive clay subsoil. Soil depth moderate to deep. Generally strongly sodic, poor upper structure, hardsetting when dry. Moderate to poor site drainage, restricted permeability.	Texture contrast, moderate nutrient holding capacity and water holding capacity (available water capacity) in upper soil. Heavy, often expansive clay subsoil. Soil depth moderate to deep. Generally strongly sodic, poor upper structure, hardsetting when dry. Poor site drainage, low permeability.	Texture contrast, moderate nutrient holding capacity and water holding capacity (AWC) in upper soil. Heavy, often expansive clay subsoil. Soil depth deep to very deep. Sodic, generally strongly, ppor upper soil structure, hardsetting when dry. Very poor site drainage and permeability.

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