SW86

SW86 landscape
‘Slickensides’ in B22 horizon indicate shrink-swell behaviour
    Site Code
SW86
SW86 profile
Vertic (& Calcic), Mottled-Mesonatric, Black SODOSOL


The large amounts of calcium carbonate present in the deeper soil are a common feature in soils in the eastern portion of the Victorian Volcanic Plain.
    Location
4 km West of Winchelsea, Ondit Road
    Landform
Gently undulating plain
    Geology
Quaternary volcanics: basalt
    Element
Depression, flat
    Slope
0
    Aspect
0
Horizon
Depth (cm)
Description
Ap
0-8 Very dark brown (10YR2/2 moist), greyish brown (10YR5/2 dry); sandy clay loam; rusty root channel mottling prominent; hard-setting; strong consistence; pH 6.2; clear boundary to:

A2
8-17 Very dark greyish brown (10YR3/2 moist and 10YR5/1 dry); loam; rusty mottling prominent (~5% fine magnetic buckshot); strong consistence; pH 6.9; abrupt boundary to:

B21tg
17-40 Very dark greyish brown (10YR3/2 moist), dark greyish brown (10YR4/2 dry) with olive grey (5Y5/2 moist) mottles in ped interiors, and prominent yellowish brown (10YR5/8 moist) mottles associated with root channels; light medium clay to medium clay; many (~25%); roughly coarse prismatic (~100 mm), parting to coarse (mostly rough-face) blocky and angular coarse blocky; very strong consistence, pH 8.1; clear boundary to:

B22ss
40-60 Very dark greyish brown (2.5Y3/2 moist); fine lenticular and polyhedral structure; moderately slickensided; pH 8.6; clear boundary to:

B23
60-80 Dark greyish brown (2.5Y4/2 moist); light medium clay; apedal; pH 8.8; clear boundary to:

B24kg
80-200 Olive to light olive grey (5Y6/2-5/3 moist); fine brownish yellow (10YR6/8 moist) mottles; soft, yellowish white carbonate; calcareous continues to 2 metres; pH 9.2.

Management considerations
The dense, coarsely-structured sodic subsoil is dispersive, restricting root growth and drainage.

The subsoil displays vertic features (i.e. slickensides) which indicates that significant shrinking and swelling occurs during wetting and drying cycles. This may have engineering implications and is likely to explain the variability in surface horizon depth across the trench. The subsoil has a high level of soluble salts, which will restrict the growth of salt-sensitive species.

Analytical data
Site SW86
Sample
depth
pH
EC
NaCl
Ex Ca
Ex Mg
Ex K
Ex Na
Ex Al
Ex acidity
FC
(-10kPa)
PWP
(-150kPa)
KS
FS
Z
C
Horizon
cm
H2O
CaCl2
dS/m
%
cmolc/kg
cmolc/kg
cmolc/kg
cmolc/kg
mg/kg
cmolc/kg
%
%
%
%
%
%
Ap
0-8
6.2
5.7
0.24
N/R
7.3
8.9
0.72
1.4
<10
12
35
17.9
20.2
30.5
14
28
A2
8-17
6.9
6.2
0.15
N/R
4
5.2
0.2
1
N/R
N/R
22.2
8.9
26.1
39.6
15
18
B21tg
17-40
8.1
7.3
0.6
0.11
4.4
12
0.7
3.8
N/R
N/R
38.7
18.2
15.1
31.8
12.5
37
B22ss
40-60
8.6
8.1
1.6
0.4
5.1
18
0.8
7.5
N/R
N/R
46.6
24.9
11.6
24.4
13
47.5
B23
60-80
8.8
8.5
2
0.46
5
19
0.7
8.1
N/R
N/R
N/R
N/R
N/R
N/R
N/R
N/R
B24kg
80-200
9.2
8.6
1.3
0.25
N/R
N/R
N/R
N/R
N/R
N/R
N/R
N/R
N/R
N/R
N/R
N/R

SW86 image 1
Rocky soil on low rises to the west of SW86
SW86 image 2
Contrasting shallow black self mulching soils on the rise and grey soils on the lower plain
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This page contains material sourced from the Victorian Resources Online (VRO) website, originally published by the State Government of Victoria. The content is licensed under the Creative Commons Attribution 3.0 Australia licence . The material has been adapted and re-formatted; no endorsement by the Victorian Government is implied.