Soil/Landform Unit 47

Undulating basaltic rises and plains near Scotchmans Lead

Area:

3026 ha

0.23% of CMA region

This unit is part of the dissected uplands associated with volcanic landforms of the Western Uplands. This unit of two occurrences of undulating rises and plains is predominantly basaltic terrain with some older sedimentary terrain and valley deposits. This unit occurs as narrow (flow) units near Linton and Buninyong surrounded by sedimentary terrain (Units

and

). The basaltic rises have red friable gradational (earth) soils (Ferrosols), which are used for intensive cropping (potatoes). The older sedimentary plains and valleys are used for grazing. The red friable soils are productive with high natural nutrient status and good drainage despite high clay contents, but are subject to compaction and structure decline after constant use when wet. The lower slopes and sedimentary plains have brown texture contrast soils (Sodosols) with hardsetting surfaces and sodic subsoils, and are subject to sheet, rill and gully erosion as well as compaction.

View west of the undulating plain of this unit

Component	1	2	3	4	5	6
Proportion of soil-landform unit	11%	11%	11%	23%	23%	21%
CLIMATE Rainfall (mm)	Annual: 690
Temperature (^oC)	Minimum 7, Maximum 18
Precipitation less than potential evapotranspiration	October-March
GEOLOGY Age and lithology	Pleistocene basalt			Ordovician slate and sandstone	Pleistocene basalt	Quaternary river deposits (gravels, sands and clays)
Geomorphology	2.1.4 Dissected Western Uplands associated with volcanic landforms
LANDUSE	Uncleared: Nature conservation Cleared: Cropping (potatoes); sheep and beef cattle grazing
TOPOGRAPHY Landscape	Undulating rises and plains
Elevation range (m)	252-552
Local relief (m)	60
Drainage pattern	Dendritic
Drainage density (km/km²)	2.3
Landform	Undulating rises			Rolling plains	Gently undulating plains	Terrace and depressions
Landform element	Crests and upper slopes	Mid slope	Lower slope and depressions	Long gentle slopes	Long gentle upper slopes
Slope and range (%)	1 (1-6)	3 (2-7)	1 (1-2)	5 (3-9)	1 (1-3)	1 (1-2)
Slope shape	Convex	Straight	Concave	Straight	Straight	Straight
NATIVE VEGETATION Ecological Vegetation Class	Plains Grassy Woodland 94.2%), Heathy Dry Forest (2.7%), Valley Grassy Forest (0.4%)
Dominant species	E. viminalis, E. radiata, E. obliqua	E. viminalis, E. radiata, E. obliqua	E. viminalis, E. radiata, E. obliqua	E. obliqua, E. viminalis	E. ovata, E. viminalis, E. rubida, E. obliqua	E. viminalis, E. radiata
SOIL Parent material	In situ weathered basalt	In situ weathered basalt	In situ weathered basalt	In situe weathered basalt	In situ weathered basalt	Unconsolidated gravel, sand, silt and clay
Description (Corangamite Soil Group)	Red gradational soil, fine structure (40)	Dark red gradational soil, fine structure (40)	Mottled brown, grey or yellow sodic texture contrast soil, coarse structure (36)	Red mottled brown, grey or yellow texture contrast soil (25)	Mottled brown, grey or yellow, grey sodic texture contrast soil, coarse structure (26)	Dark brown soil - variable (34)
Soil type sites	BD5, SW96, SW26	BD5, SW96, SW26	SFS6, MM5015, CLRA47	BD10, CRLA54, CLRA58	BD13, BD11, MM204	SW39, CLRA15, CLRA1
Surface texture	Clay loam	Loam	Clay loam	Loamy clay	Clay loam	Fine sandy clay loam
Permeability	High	High	Moderate to low	Moderate to low	Moderate to low	Moderate to low
Depth (m)	2	1.5	1.5	1	1.5	2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Exposed slopes lead to overland flow and sheet erosion. Leaching and nutrient decline also commonly occur.	Hardsetting surface soils can lead to compaction and are subject to overland flow and sheet erosion on moderate slopes. Leaching and nutrient decline also commonly occur.	Hardsetting surface soils can lead to compaction, while low permeability and waterlogging are features of these soils.	Hardsetting surface soils can lead to compaction and are subject to overland flow, gully, sheet and rill erosion on moderate slopes. Leaching of nutrients also occur on these soils.	Hardsetting surface soils can lead to compaction and slowly permeable subsoils lead to periodic waterlogging. Overland flow and sheet erosion may also occur on these soils.	Low-lying areas receiving drainage leads to waterlogging of soils. Overland flow can lead to streambank erosion and gully erosion.

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