Soil/Landform Unit - Kalkee plains2

Cultivated Kalkee plains near Carron with minor drainage system defined by lines fo remnant vegetation

Area: 36 167 ha

1.54% of CMA region

North of the Wimmera River as it emerges from the Dissected Western Uplands are the clay plains for which the Wimmera is renowned. The Kalkee plains are synonymous with the

self-mulching

grey clays that have supported cereal cropping for much of the last century. These clay plains (Kalkee plains) have been divided into two units with this unit comprising a significant proportion of coloured variants to the traditional Kalkee clay. These clay soils are only found west of the Yarriambiack River. Comprising very gentle rises and plains, drainage across these plains is very subtle and often poorly defined. The self-mulching

Vertosols

have high clay contents that can be variable due to micro relief and presence of

gilgai

. Soils may also be susceptible to inundation and periodic waterlogging during significant rainfall events. The dominant remnant vegetation community is Plains Savannah. Other remnant vegetation includes Low Rises Woodland, Plains Woodland, Riverine Chenopod Woodland and Plains Grassland.

Cultivated land with gilgai

Component	1	2	3	4
Proportion of soil-landform unit	5%	10%	78%	7%
CLIMATE Rainfall (mm)	Annual: 402
CLIMATE Rainfall (mm)	Annual: 402
Temperature (^oC)	Minimum 9, Maximum 21
Precipitation less than potential evapotranspiration	September–April
GEOLOGY Age and lithology	Neogene marine sand and silt (Parilla Sand); Quaternary alluvium, gravel, sand and silt
GEOLOGY Age and lithology
Geomorphology	5.4 Clay plains with subdued ridges of the North West Dunefields and Plains
LANDUSE	Uncleared areas: nature conservation Cleared areas: dryland cropping; sheep grazing
LANDUSE
TOPOGRAPHY Landscape	Gently undulating plains (Kalkee plains)
TOPOGRAPHY Landscape	Gently undulating plains (Kalkee plains)
Elevation range (m)	104–155
Local relief (m)	2
Drainage pattern	Dendritic
Drainage density (km/km²)	0.4
Landform	Very gentle rises		Plains
Landform element	Low rise crest	Low rise slope	Plain	Swamp/drainage depression
Slope and range (%)	3 (1-7)	5 (3-10)	3 (1-8)	0 (0-3)
Slope shape	Convex	Convex	Concave	Concave
NATIVE VEGETATION Ecological Vegetation Class	Plains Savannah (36.9%), Plains Woodland (20.6%), Riverine Chenopod Woodland (15.3%), Plains Grassland (11.1%), Other (9.0%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	Aeolian sand and silt	Aeolian sand and silt	Marine sand and silt, and paludal silt and clay	Paludal silt and clay
SOIL Parent material	Aeolian sand and silt	Aeolian sand and silt	Marine sand and silt, and paludal silt and clay	Paludal silt and clay
Description (Corangamite Soil Group)	Cracking clay soils (34) and sodic red texture contrast soils (39)	Cracking clay soils (34)	Cracking clay soils (34)	Seasonally wet soils: sodic yellow and grey texture contrast soils (33) and cracking clay soils (34)
Soil type sites	WIA6, WIA9, NA174	WIA6, WIA9, WIA5	WIA6, WIA9, WIA5	NA171, NA141, WIA6
Surface texture	Sandy loam to medium clay	Medium clay	Medium clay	Light clay
Permeability	Moderate	Moderate	Moderate	Slow
Depth (m)	1.5	> 3	> 3	> 3
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Hardsetting upper soil susceptible to sheet and rill erosion along with wind erosion when exposed. High clay surfaces result in restricted soil drainage, but can be variable due to micro relief (gilgai).Dispersive and deep subsoils susceptible to gully erosion on steeper slopes. Compaction of upper soil variable depending on soil depth and moisture content. Upper soil is susceptible to acidification.	High clay content results in restricted soil drainage, but can be variable due to micro relief (gilgai). Soils may be susceptible to inundation and waterlogging. Surface soils are friable and only slightly susceptible to wind erosion due to self-mulching and massive nature. Soils may be susceptible at critical moisture contents and have variable resilience to compaction.	High clay content results in restricted soil drainage, but can be variable due to micro relief (gilgai). Soils may be susceptible to inundation and waterlogging. Surface soils are friable and only slightly susceptible to wind erosion due to self-mulching and massive nature. Soils may be susceptible at critical moisture contents and have variable resilience to compaction.	Susceptible to seasonal inundation, waterlogging and ultimately soil salinity. Upper soils susceptible to sheet erosion and wind erosion when exposed.

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