Soil/Landform Unit - Kybybolite plains

Plains near the Victoria-South Australia border

Area: 4033 ha

0.17% of CMA region

Located on the border of Victoria and South Australia, these gently undulating plains comprise gentle rise crests and plains of flats and slopes. Lining western extents of the Tallageira soil-landform unit, the plains form part of the low ridge tops with remnant aeolian sands and orientated swales with lakes and

lunettes

(5.5.2) geomorphology sequence. Soils of the plains are

sodic

brown, yellow and grey texture contrast soils (

Sodosols

) with varying depths of surface sand. These sandy surfaces maybe susceptible to wind and sheet erosion where exposed. The strong texture contrast with loose sands over clays has implications for site drainage also. This is reflected in irrigated horticulture where vegetables etc. are grown on these sandy soils and applied waters are recaptured through a series of shallow drains. These drains are usually dug to the top of the subsoil where water infiltration is extremely slow. The dominant vegetation communities are Plains Woodland, Red Gum Wetland, Shallow Sands Woodland and Red Gum/Aquatic Herbland Mosaic. Other vegetation present includes Damp Sand Herb-rich Woodland, Heathy Woodland and Drainage-line Woodland.

Red gum and allcasuarine trees on a plain near Tallageira
	Centre pivot irrigator on a cleared undulating rise near Tallageira

Component	1	2
Proportion of soil-landform unit	90%	10%
CLIMATE Rainfall (mm)	Annual: 560

Temperature (^oC)	Minimum 8, Maximum 21
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Quaternary paludal silt and clay; Neogene marine sand and silt (Parilla Sand)

Geomorphology	5.5.2 Low ridges and oriented swales of the North West Dunefields and Plains
LANDUSE	Uncleared areas: nature conservation Cleared areas: dryland cropping; sheep grazing

TOPOGRAPHY Landscape	Gently undulating plains

Elevation range (m)	96–132
Local relief (m)	2
Drainage pattern	Dendritic–deranged
Drainage density (km/km²)	0.2
Landform	Plains	Rises
Landform element	Flat/gentle slope	Rise slope/crest
Slope and range (%)	3 (1-7)	5.(2-9)
Slope shape	Straight	Convex
NATIVE VEGETATION Ecological Vegetation Class	Plains Woodland (60.4%), Red Gum Wetland (20.5%), Shallow Sands Woodland (8.4%), Other (9.2%)

SOIL Parent material	Marine sand and silt	Marine sand and silt

Description (Corangamite Soil Group)	Sodic brown, yellow and grey texture contrast soils (38)	Sodic brown, yellow and grey texture contrast soils (38)
Soil type sites	LSWW11, LSWW17, LSWW13	LSWW11, LSWW17, LSWW13
Surface texture	Loamy sand	Loamy sand
Permeability	Moderate	Moderate
Depth (m)	> 1.5	1.3
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Susceptible to wind and sheet erosion where exposed. Susceptible to compaction where hardsetting and restricted drainage. Strong texture contrast with loose sands over clays has implications for site drainage.	Susceptible to wind and sheet erosion on slopes where exposed. Susceptible to compaction where hardsetting and restricted drainage. Upper soil is susceptible to acidification.

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