Your gateway to a wide range of natural resources information and associated maps

Victorian Resources Online

GHF07c

Location: Mumbannar

Australian Soil Classification: Melacic-Parapanic, Humic/Humosesquic, Semiaquic, PODOSOL
General Landscape Description: Gently undulating plain
Site Description: Lower slope
Land Unit: Strathdownie
Geology: Quaternary lacustrine

General Land Unit Description: This land unit comprises the Quaternary lacustrine geology south of the Glenelg River. The lacustrine deposits include lagoonal, swamp and local colluvial deposits formed in low-lying wetlands and depressions between stranded beach ridges. Parent material in this land unit comprises of sand, silt, sandy clay, peat, marl and freshwater limestone, occurring in relatively unconsolidated forms.

The soils are variable throughout this land unit due to varying depositional environments. A common soil type is a strong texture contrast soil (Chromosol, Sodosol) commonly with a bleached A2 horizon and a mottled subsoil (indicative of impeded internal drainage). The sandy topsoil can be very deep in some soils. Vertosols are also common on the plains and swales in between the dunes. Podosols occur on the flats as well as on the dunes and that may have been mapped as part of this land unit due to restrictions of scale. Many of the soils are poorly drained and exhibit signs of a perched watertable.

1.5 year old Eucalyptus globulus plantation on ex-agricultural land.

Soil pit Hun99 1-5 landscape

Soil Profile Morphology

A10-20 cmVery dark grey (10YR3/1); loamy fine sand; single grain structure; loose consistence, moist; many medium roots present; pH 4.7; clear and smooth change to:


Soil pit Hun99 3 profile
A220-70 cmGreyish brown (10YR5/2), conspicuously bleached; fine sand; single grain structure; loose consistence, moist; common very fine roots present; pH 4.6; abrupt and smooth change to:


Subsoil


Bh70-80 cmBlack (10YR2/1); loamy fine sand; single grain structure; loose consistence, moist; many very fine roots present; pH 4.5; abrupt and smooth change to:


Bhs80-100 cmVery dark brown (10YR2/2), with many coarse distinct strong brown (7.5YR5/6) mottles, loamy fine sand; massive structure; strong consistence, moderately moist; moderately cemented continuous massive organic pan evident; pH 4.6; abrupt and wavy change to:


B2100-115 cmVery pale brown (10YR7/3), with common fine dark yellowish brown (10YR4/4) and reddish yellow (7.5YR6/8) mottles; fine sandy clay; weak coarse angular blocky structure; very weak consistence, wet; pH 4.9; clear and wavy change to:


B3115-150 cmVery pale brown (10YR7/3), with common fine distinct reddish yellow (7.5YR6/8) mottles; clayey fine sand; single grain structure; loose consistence, wet; pH 6.2; changes to:


150-200 cmSand; changes to:


200-250 cmSand; soft limestone (CaCO3) and limestone nodules present; changes to:


250-300 cmSand; increasing limestone with depth; becoming very hard and impenetrable at 300 cm.


C300 + cmLimestone.




Soil Profile Characteristics:
-

pH
Salinity
Surface Soil
(A1 horizon)
Very Strongly Acid
Very Low
Subsoil
(70-80 cm)
Very Strongly Acid
Very Low
Deeper Subsoil
(115-150 cm)
Slightly Acid
Very Low




Chemical and Physical Analysis:
Horizon
Horizon Depth
(cm)
pH
(water)
pH
(CaCl
2)
EC
dS/m
Organic Carbon
%
Total
Nitrogen
%
A1
0-20
4.7
3.8
<0.05
1.5
0.08
A2
20-70
4.6
3.8
<0.05
Bh
70-80
4.5
3.7
<0.05
1.3
0.08
Bhs
80-100
4.6
4.0
<0.05
B2
100-115
4.9
4.1
<0.05
B3
115-150
6.2
5.4
0.05

Management Considerations:
Free water at 150 cm and at 300 cm. The density of limestone at 300 cm suggests that there may be an impeding layer to root growth at this depth, but some data from Forestry SA indicates that the presence of shallow limestone may not necessarily restrict root development.


Profile Described By: Ian Sargeant, Paul Feikema, Martin Clark and Kiet Quach, 5th December 2000.
Page top