Soil/Landform Unit 204

The You Yangs are a prominent residual granite of the Western Plains

Area:

3451 ha

0.26% of CMA region

This unit consists of undulating low hills on colluvium associated with the You Yangs, on the eastern border of the catchment. The granite derived colluvial slopes of the Western Plains includes the landform components crests and upper slopes, mid slopes and lower slopes. There is little dissection of this mantle. The soils range from

sodic

mottled

brown or grey texture contrast soils (

Sodosols

Chromosols

), often with deep sandy upper soils on the crests to strongly sodic mottled brown or grey texture contrast soils (Sodosols) on mid and lower slopes.

Rainfall is relatively low in this area and land use is generally grazing (sheep) with some cropping. Softwood plantations are also common on slopes. These soils are susceptible to sheet and rill erosion and possibly tunnel and gully erosion on steeper and lower slopes.

The colluvial slopes of the You Yangs are surrounded by alluvial and basalt plains

Component	1	2	3	4
Proportion of soil-landform unit	15%	30%	47%	8%
CLIMATE Rainfall (mm)	Annual: 510
CLIMATE Rainfall (mm)	Annual: 510
Temperature (^oC)	Minimum 9, Maximum 20
Precipitation: less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Neogene fluvial-marine sediments, Recent clay, sand and gravel, Devonian granitic intrusive
GEOLOGY Age and lithology
Geomorphology	6.3.1 Granitic hill inliers of the Western Plains
LAND USE	Uncleared: Nature conservation Cleared: Hardwood and softwood plantations; beef cattle and sheep grazing; cropping (cereal)
TOPOGRAPHY Landscape	Colluvial slopes associated with the You Yangs
TOPOGRAPHY Landscape	Colluvial slopes associated with the You Yangs
Elevation range (m)	24–223
Local relief (m)	50
Drainage pattern	Dendritic
Drainage density (km/km²)	1.8
Landform	Hills and slopes			Drainage lines
Landform element	Crests and upper slopes	Mid slopes	Lower slopes
Slope and range (%)	12 (6–20)	8 (4–15)	5 (2–10)	2 (1–5)
Slope shape	Convex	Convex	Concave	Convex
NATIVE VEGETATION Ecological Vegetation Class	Hills Herb-rich Woodland (0.9%), Plains Grassy Woodland (0.3%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	Colluvial clay, silt and sand	Colluvial clay, silt and sand	Colluvial clay, silt and sand	Alluvial clay, silt and sand
SOIL Parent material	Colluvial clay, silt and sand	Colluvial clay, silt and sand	Colluvial clay, silt and sand	Alluvial clay, silt and sand
Description (Corangamite Soil Group)	Acidic mottled brown and grey texture contrast soils and alkaline mottled brown and grey texture contrast soils (2/4)	Alkaline mottled brown, grey or yellow texture contrast soils (14)	Alkaline mottled brown, grey or yellow texture contrast soils (14)	Alkaline mottled brown, grey or yellow texture contrast soils (32)
Soil type sites	MM162, BD8, MM236	SW99, SW93, MM204	SW99, SW93, MM204	SW88, SW95, CLRA4
Surface texture	Coarse sandy clay loam, sandy loam	Sandy loam	Sandy loam	Sandy loam
Permeability	Moderate to high	Moderate	Low	Very low
Depth (m)	<1	<2	<2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Rock outcrop or stony. Texture contrast with coarse sand component. Low nutrient holding capacity in upper soil, high in subsoil. Permeable surface sands of high acidity and low inherent fertility are prone to nutrient decline Moderately rapid site drainage.	Texture contrast with coarse sand component. Low nutrient holding capacity in upper soil, high in subsoil. Permeable surface sands of high acidity and low inherent fertility are prone to nutrient decline. Moderately rapid site drainage.	Texture contrast with coarse sand component. Low nutrient holding capacity in upper soil, high in subsoil. Permeable surface sands of high acidity and low inherent fertility are prone to nutrient decline. Slow to moderate site drainage.	Texture contrast with coarse sand component. Low nutrient holding capacity in upper soil (where little organic matter), high in subsoil. Permeable surface sands of high acidity and low inherent fertility are prone to nutrient decline. Very slow site drainage.

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