Soil/Landform Unit - Murra Warra East gentle rises

WLRA Landform Murra Warra East gentle rises

Red soils east of the Yarriambiack Creek are often on gentle to undulating rises

Area: 62 317 ha

2.66% of CMA region

The landscape comprises large and some small discreet depositional entities that form the lower part of an extensive plains complex south-east of Warracknabeal and north-east of Murtoa. As part of North West Dunefields and Plains; clay plains with subdued ridges unit (5.4), the extensive

alluvial

(and

aeolian

) plains of

Quaternary

sediments with occasional rises is bound by the Yarriambiack Creek to the west, and subdued dunefields (Beulah) and alluival plains (Charlton) to the north. To the south and east lie a plains complex with alluvial and paludal plains. Dunmunkle Creek flowing south to north dissects the unit.

Drainage is mainly dendritic and extensive away from the main drainage lines, which may be anastomotic. Site drainage is generally slow. Soils include red sodic texture contrast soils (

Sodosols

) and grey cracking clay soils (

Vertosols

Hardsetting

surfaces are common where exposed. Broadacre dryland cropping is the major enterprise with minor grazing (sheep and cattle). Plains Savannah and Plains Woodland are the most expansive remnant vegetation communities recorded.

Bean crop on gently undulating rises and plains
	Cereal harvesting

Component	1	2
Proportion of soil-landform unit	95%	5%
CLIMATE Rainfall (mm)	Annual: 390

Temperature (^oC)	Minimum 9, Maximum 21
Precipitation less than potential evapotranspiration	September–April
GEOLOGY Age and lithology	Quaternary fluvial silt, sand and minor gravel (Shepparton Formation); Neogene marine sand and silt (Parilla Sand); Quaternary paludal silt and clay

Geomorphology	5.4 Clay plains with subdued ridges of the North West Dunefields and Plains; 5.1.5 Hummocky dunes sub-dominant of the Calcareous North West Dunefields and Plains
LANDUSE	Uncleared areas: nature conservation Cleared areas: dryland cropping; sheep and beef cattle grazing

TOPOGRAPHY Landscape	Moderately undulating plains

Elevation range (m)	104–153
Local relief (m)	3
Drainage pattern	Dendritic
Drainage density (km/km²)	0.4
Landform	Undulating plains
Landform element	Plain	Playa
Slope and range (%)	2 (1-5)	1 (0-3)
Slope shape	Straight	Concave
NATIVE VEGETATION Ecological Vegetation Class	Plains Savannah (42.2%), Plains Woodland (31.6%), Low Rises Woodland (11.3%), Ridged Plains Mallee (8.5%), Other (3.0%)

SOIL Parent material	Marine sand and silt	Paludal silt and clay

Description (Corangamite Soil Group)	Sodic red texture contrast soils (27) and cracking clay soils (34)	Cracking clay soils (34)
Soil type sites	TopCrop2, LS17, WIA6, WIA9	WIA6, WIA9, WIA5
Surface texture	Sandy loam to medium clay	Medium clay
Permeability	Moderate to slow	Slow
Depth (m)	> 3	> 3
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Hardsetting surfaces susceptible to sheet and rill erosion. High clay content results in restricted soil drainage. Soils are prone to compaction at critical moisture contents. Clay surface soils are friable and only slightly susceptible to wind erosion due to self-mulching and massive nature	High clay content results in restricted soil drainage, but can be variable due to micro relief (gilgai). Plain may be subject to periodic 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.

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