Soil/Landform Unit 48

Soils on lower slopes are vulnerable to waterlogging, soil salting and nutrient decline. The presence of Eucalyptus ovata is indicative of poorly drained soils

Area:

1161 ha

0.09% of CMA region

The undulating rises of Quaternary volcanics north of Ballan is located on the eastern boundary of the Corangamite catchment. Over 85% of the land is cleared for private use. The main vegetation class is the Herbrich Foothill Forest.

Eucalyptus ovata

is prevalent over much of the area due to the poorly drained manner of most soils. The weathered basalt has reasonable inherent fertility levels and a moderate water holding capacity. In the past the forest has provided sawn timber, posts and firewood; softwood plantations are now prominent in the area. Soils include acidic and neutral mottled texture contrast soils. There are minor occurrences of shallow alkaline brown cracking clays. Waterlogging is common throughout the landscape, and these areas tend to have strongly sodic subsoils. As a result, soil salting is often expressed at the surface.

Pastures grown for hay (including clover shown here) is an infrequent land use
	Gentle slopes are prone to waterlogging and pugging from cattle

Component	1	2	3	4	5	6
Proportion of soil-landform unit	55%	1%	1%	3%	30%	10%
CLIMATE Rainfall (mm)	Annual: 860
Temperature (^oC)	Minimum 7, Maximum 17
Precipitation less than potential evapotranspiration	November-March
GEOLOGY Age and lithology	Quaternary basalt, Ordovician marine shale and sandstone, Neogene fluvio-marine sand
Geomorphology	2.1.4 Dissected Western Uplands associated with volcanic landforms
LANDUSE	Uncleared: Water supply; nature conservation Cleared: Sheep and cattle grazing cropping (cereal and pasture); softwood plantations
TOPOGRAPHY Landscape	Undulating rises
Elevation range (m)	500-611
Local relief (m)	2
Drainage pattern	Dendritic
Drainage density (km/km²)	1.9
Landform	Slightly dissected undulating plain			Rolling plain and rises		Drainage depression and terrace
Landform element	Long gentle upper slopes	Depression	Stony rise	Crest	Long gentle slope
Slope and range (%)	2 (1-3)	1 (1-2)	3 (2-5)	1 (1-3)	5 (3-9)	1 (1-2)
Slope shape	Straight	Straight	Convex	Convex	Straight	Straight
NATIVE VEGETATION Structure	-	-	-	Woodland	Open forest	Woodland
Dominant species	E. ovata, E. viminalis, E. rubida, E. obliqua	E. ovata, E. viminalis, E. rubida, E. obliqua	E. ovata, E. viminalis, E. rubida, E. obliqua	E. obliqua, E. radiata	E. obliqua, E. viminalis	E. viminalis, E. radiata
SOIL Parent material	In situ weathered basalt	Alluvium	In situ weathered basalt	In situ weathered sandstone and shale	In situ wathered sandstone and shale	Unconsolidated gravel, sand, silt and clay
Description (Corangamite Soil Group)	Mottled brown, grey or yellow sodic texture contrast soil, coarse structure (36, 35)	Black clay soil, uniform texture, coarse structure (31)	Red shallow, stony gradational soil (40)	Shallow stony red gradational soil (25)	Red mottled brown, grey or yellow texture contrast soil (25)	Dark brown soil - variable (34)
Soil type sites	SFS19c, CLRA47, SW90	CLRA15, SW37, CLRA48	BD5, SW96, SW26	CLRA57, CLRA53, BD10	CLRA57, CLRA53, BD10	CLRA1, SW39, CLRA15
Surface texture	Clay loam	Clay	Clay loam	Gravelly loam	Loamy clay	Fine sandy clay loam
Permeability	Moderate to low	Moderate	High	High	Moderate to low	Moderate to low
Depth (m)	1.5	1.5	0.5	0.6	1	2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Low to moderate water holding capacity. Upper soil susceptible to sheet and rill erosion with increasing slope. Waterlogging is common with strongy sodic subsoils. Soil are hardsetting and mottled.	Clay soils beside creeks are prone to waterlogging. Streambank undercutting and streambank erosion can occur with excessive rains and inadequate ground coverage.	Overland flow is likely to cause sheet and rill erosion. Nutrient decline is possible due to shallow and permeable soils.	Moderate slopes and hardsetting surfaces result in significant overland flow. Sheet and rill erosion also occur from this overland flow. Soil salting and discharge is an issue. Soil compaction is also a limitation for soils with shallow topsoils.	Moderate slopes and hardsetting surfaces result in significan overland flow. Sheet and rill erosion also occur from this overland flow. Soil salting and discharge is an issue. Soil compaction is also a limitation for soils with shallow topsoils.	Low-lying areas receiving drainage experience waterlogging. Overland flow is likely to cause sheet and rill, streambank and gully erosion.

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