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

Victorian Resources Online

LP38

Property: State ForestAustralian Soil Classification: Acidic-Sodic, Eutrophic (nearly Magnesic), Red DERMOSOL
Northcote Factual Key: Um 2.21Geology: Cambrian marine sediments (shale, quartz).
General Landscape Description: Upper slope of hillslope in State Forest. Vegetation includes Ironbark (Eucalyptus sideroxylon), Grey Box (E. microcarpa) and Golden Wattle (Acacia pycnantha). This site is located approximately 3 km south-west of St Arnaud.

Photo: Soil Pit Site LP38 Landscape
Site LP38 Landscape


Soil Profile Morphology

Surface Soil

A10-5 cmBrown (7.5YR4/4); sandy clay loam; weakly structured; hardsetting surface condition; firm consistence dry; contains many (25%) siltstone fragments and a few (5%) quartz fragments; pH 5.1; clear change to:
Photo: Pit Site LP38 Soil Profile
Site LP38 Profile










A25-25 cmYellowish red (5YR5/6) conspicuously bleached; light fine sandy clay loam; structureless; strong consistence dry; contains a common (15%) amount of siltstone and few (10%) quartz gravels; strong consistence dry; pH 4.9; clear and wavy change to:
Subsoil
B2125-45 cmYellowish red (5YR5/6); fine sandy clay loam; weak medium blocky structure; very strong consistence dry; contains few (10%) siltstone and very few (1%) quartz fragments; pH 5.3; wavy change to:
B2245-55 cmYellowish red (5YR5/6); fine sandy clay loam; moderate medium blocky structure; strong consistence dry; pH 6.0; wavy change to:
C55 cm +Weathering siltstone material; contains a 1 cm thick layer of yellowish red clay at 65 cm depth.

Key Profile Features
  • Lack of strong texture contrast between surface (A) horizons and subsoil (B) horizons.
Key Profile Characteristics

pH
Salinity Rating
Surface
(A1 horizon)
strongly acid
very low
non-sodic
none
Subsoil
(25-45 horizon)
strongly acid
low-medium
non-sodic
moderate
Deeper subsoil
(45-55 cm)
moderately acid
medium
sodic
strong

Graph: pH levels in Soil Pit Site LP38
Graph: Salinity levels in Soil Pit Site LP38
Graph: Sodicity levels in Soil Pit Site LP38


Horizon
Horizon Depth
pH (water)
pH CaCl2
EC 1:5
NaCl
Exchangeable Cations
Ca
Mg
K
Na
Meq/100g
A1
0-5
5.1
4.3
0.17
1.1
1.4
0.7
0.3
A2
5-25
4.9
4.3
0.31
0.3
1.9
0.4
0.2
B21
25-45
5.3
4.7
0.43
1
3.4
0.3
0.4
B22
45-55
6
5.4
0.55
0.1
3.7
0.3
0.7
C
55

Horizon
Horizon Depth
Ex Al
mg/kg
Ex Ac
meq/100g
Field
pF2.5
Wilting Point
pF4.2
Coarse Sand
(0.2-2.0mm)
Fine Sand
(0.02-0.2mm)
Silt
(0.002-0.02mm)
Clay
(<0.002mm)
A1
0-5
66
15.8
27.1
11.5
A2
5-25
51
7.6
22.5
10.2
B21
25-45
11
5.8
26.6
11.9
3.1
32
43
23
B22
45-55
3.3
34.6
37.5
24.5
C
55

Management Considerations:

Surface (A) Horizons
  • The surface soil is strongly acid. Aluminium becomes more soluble in soils at low pH levels. The level of exchangeable aluminium measured in the laboratory for this pit site I s reasonably high (i.e. > 50 ug/g) may restrict the growth of highly aluminium sensitive species.
  • Deficiencies in the trace element molybdenum (Mo) are likely to occur in strongly acid soil. Soil adsorption of Mo increases as pH decreases, leading to reduced availability to plants. Deficiencies in other nutrients (e.g. potassium, phosphorus and calcium) may also occur.
  • The surface horizons have a very low inherent fertility (based on the sum of the basic exchangeable cations).
Subsoil (B) Horizons
  • The subsoil also has a low inherent fertility (based on the sum of the exchangeable basic cations).
  • The subsoil has a high percentage of exchangeable magnesium in relation to other cations. Nutrient imbalances may occur as a result (e.g. calcium deficiency).
Notes:
  • Profile described by Mark Imhof, Paul Rampant and Karen De Plater (21/3/95).
Page top