Soil/Landform Unit 19

Undulating low granitic hills south of Pittong. A blue gum plantation is evident on the lower colluvial slopes on these hills

Area:

4018 ha

0.30% of CMA region

The undulating to gently undulating low granitic hills south of Pittong are part of the granitic landscapes within the Midlands of the Western Uplands. This

Devonian

granite unit is located south of Pittong in the north of the catchment. The gentle to undulating slopes graduate into the prominent footslopes, drainage depressions and

alluvial

fans of Unit

. Remnant vegetation on the granite is sparse with the Grassy Woodland, Heathy Dry Forest and Riparian Woodland among the major classes. The soils consist of an association of mottled texture contrast soils and deep brown sands. Areas of rocky outcrop occur on the upper slopes and crests with deep sands. Minor

mottled

sodic

texture contrast soils occur on the mid to lower slopes. Unbleached mottled texture contrast soils with lighter textured surfaces may also occur on some of the lower crests. Land use is restricted to grazing and cropping due to the low available water holding capacity and ready leaching of nutrients from these soils. Gully erosion occurs to a moderate extent and is difficult to control on the steeper slopes and valleys of these hills. Salting is also expressed at the surface as evidenced by the presence of spiny rush.

Undulating hillslopes south of Pittong
	Looking north-east towards the Late Devonian granite

Component	1	2	3
Proportion of soil-landform unit	15%	30%	55%
CLIMATE Rainfall (mm)	Annual: 680
Temperature (^oC)	Minimum 7, Maximum 18
Precipitation less than potential evapotranspiration	November-March
GEOLOGY Age and lithology	Devonian granite
Geomorphology	2.1.2 Dissected Western Uplands associated with granitic rocks and aureoles
LANDUSE	Uncleared: Nature conservation Cleared: Sheep grazing; limited cropping (cereal)
TOPOGRAPHY Landscape	Undulating slopes of the low granite hills
Elevation range (m)	266-392
Local relief (m)	60-100
Drainage pattern	Dendritic
Drainage density (km/km²)	2.0
Landform	Hill slopes
Landform element	Low crests	Upper and mid slopes	Lower slopes
Slope and range (%)	2 (1-5)	5 (3-10)	2 (1-5)
Slope shape	Convex	Convex	Concave
NATIVE VEGETATION Ecological Vegetation Class	Grassy Woodland (0.3%)
SOIL Parent material	Granite	Granite	Granite
Description (Corangamite Soil Group)	Mottled brown, grey or yellow texture contrast soils with light textured surfaces (3)	Acidic mottled brown, grey or yellow texture contrast soils (3)	Sodic mottled brown, grey or yellow texture contrast soils (2)
Soil type sites	MM5150	MM5150	MM162, MM411
Surface texture	Coarse sandy clay loam	Coarse sandy clay loam	Sandy clay loam
Permeability	Moderate	High	Very low
Depth (m)	<1.5	>2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Uniform sands with prominent texture contrast, very low nutrient holding capacity and water holding capacity in sandy coils, high in underlying clays. Susceptibility to deep seepage, nutrient decline and sheet erosion.	Moderate slopes, low permeability and hardsetting surfaces result in overland flow. Subsurface flow (deep sandy surface soil) and deep seepage combine in leaching of salts, rilly and gully erosion, as well as sheet erosion.	Moderate slopes, low permeability and harsetting surfaces result in overland flow. Subsurface flow (deep sandy surface soil) and deep seepage combine in leaching of salts, rill and gully erosion, as well as sheet erosion.

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