Soil/Landform Unit 173

These gently undulating sedimentary plains are mainly used for cropping and grazing

Area:

1101 ha

0.08 % of CMA region

This unit is a gently undulating sedimentary plain within the Western Plains. This unit is a small unit of two occurrences (east of Bannockburn and north of Anakie) consisting of very low relief and slow site drainage, apart from the drop to lower terrain. The main occurrence is north-west of Moorabool and is bound east and west by incised drainage valleys (including the Moorabool River valley) and is influenced by basaltic material from the north. The soils are alkaline texture contrast soils that are generally strongly sodic with poor permeability and mainly used for grazing. The surface soils are light (mainly sandy loams) with a limited nutrient holding capacity and poor structure, influenced by the sodic subsoil.

Undulating basalt plain east of Bannockburn
	Undulating basalt plain highlighting basalt rocks at the surface.

Component	1	2	3
Proportion of soil-landform unit	95%	3%	2%
CLIMATE Rainfall (mm)	Annual: 550
Temperature (^oC)	Minimum 9, Maximum 19
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Neogene fluvial and marine sediments, Quaternary basalt and minor Paleogene tholeiites and pyroclastics
Geomorphology	6.2.4 Plains, rises and low hills of the Sedimentary Western Plains
LANDUSE	Uncleared: Nature conservation Cleared: Beef cattle and sheep grazing; occasional cropping (cereal)
TOPOGRAPHY Landscape	Undulating plains
Elevation range (m)	45–147
Local relief (m)	3–5
Drainage pattern	Dendritic
Drainage density (km/km²)	0.7
Landform	Long gentle slopes	Drainage line	Stony rises
Landform element	Slopes	Depression
Slope and range (%)	1 (1–3)	1 (1–2)	3 (2–5)
Slope shape	Straight	Straight	Convex
NATIVE VEGETATION Ecological Vegetation Class	Plains Grassy Woodland (0.1%)
Dominant species	E. leucoxylon
SOIL Parent material	Unconsolidated sediments (sand and clay) with in situ weathered rock	Alluvium	In situ weathered basalt
Description (Corangamite Soil Group)	Mottled dark grey sodic texture contrast soils, coarse structure (13/36)	Black clay soils, coarse structure (31)	Red shallow stony gradational (earths and loams) soil (40)
Soil type sites	MM5015, SW99, SFS6	SW37, CLRA48, MM5015	SW96, SW26, BD5
Surface texture	Sandy loam	Clay	Clay loam
Permeability	Moderate to low	Low	High
Depth (m)	1.0–3.0	1.0–3.0	0.2–0.5
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Hardsetting surfaces, slowly permeable subsoil and overland flow can cause periodic waterlogging. Surface compaction and sheet erosion may also occur.	Clay soils in drainage line may experience waterlogging. Overland flow may lead to rill erosion.	Slopes and overland flow contribute to sheet erosion. Leaching and nutrient decline also occur.

Page top