SFS19

Location: Teesdale.

Australian Soil Classification: Vertic (& Ferric), Mottled-Subnatric, Brown SODOSOL

General Landscape Description: Level Plain.
Site Description: Southern Farming Systems (SFS) raised bed site.
Land Use: Canola.
Geology: Moorabool Viaduct Formation

SFS19 Landscape.

Surface Soil			SFS19 Profile.
Ap	0-10 cm	Dark brown (10YR3/3); light sandy loam; weakly pedal structure tending to platy at bottom of Ap; weak consistence dry; pH 6.3; clear change to:
A2c	10-30 cm	Yellowish brown (10YR5/4) conspicuously bleached (10YR6/3 dry); gravelly loam; apedal structure; weak consistence dry; very many medium to coarse (5-20 mm in size) irregular cemented ferruginous nodules (remnants of Moorabool Viaduct sand) as well as rounded quartz alluvial gravel; pH 5.1; sharp and smooth change to:
Subsoil
B21t	30-60/70 cm	Brown (10YR5/3) with reddish yellow (7.5YR6/8) mottles; medium clay; strong coarse prismatic, parting to strong medium to coarse blocky and strong fine to medium polyhedral and lenticular structure; strong consistence dry; slickensides evident with thick cutans; pH 6.7; clear change to:
B/C	60/70-80 cm	Dark red (10R3/6) and red (10R5/8) with coarse reddish yellow (7.5YR6/8) and light grey (2.5Y7/1) mottling; weathered ferruginised Moorabool Viaduct Formation sediments with clay accumulation; rigid ferruginised masses of sandier material than B21 above but with reticulate structure defined by thick bands of illuviated clay; pH 7.6.
C	80+ cm	Weathered ferruginised Moorabool Viaduct Formation sediments.

• Strong texture contrast between surface (A) horizon and subsoil (B21) horizon.
• Conspicuously bleached subsurface (A2) horizon with ferruginous nodules.

The pH in the surface is slightly acid. The pH in the upper subsoil is slightly acid becoming slightly alkaline with depth.

The salinity rating is low in the surface becoming very low in the subsoil.

The surface is non sodic. The upper subsoil is marginally sodic becoming sodic with depth.

The clay content in the surface is low and sharply increases at the surface / subsoil interface.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC dS/m	NaCl %	Exchangeable Cations
						Ca	Mg	K	Na
						meq/100g
AP	0-10	6.3	6.1	0.22	0.01	3.3	0.7	0.5	<0.1
A2	10-30	5.1	4.5	0.05		0.88	0.25	0.24	<0.05
B21+	30-60/70	6.7	6.2	0.15		5.4	7.9	1.4	0.79
C/B	60/70-80	7.6	6.8	0.12		2.8	5.7	0.45	1.3

Horizon	Horizon Depth (cm)	Exchangeable Aluminium mg/kg	Exchangeable Acidity meq/100g	Oxidisable Organic Carbon %	Total Nitrogen %	Field Capacity pF2.5	Wilting Point pF4.2	Coarse Sand (0.2-2.0 mm)	Fine Sand (0.02-0.2 mm)	Silt (0.002-0.02 mm)	Clay (<0.002 mm)
AP	0-10	<10	6.9	2.6	0.29	10.4	6.4	60.4	23.8	3.0	7.5
A2	10-30	18	3.7			7.0	2.6	58.7	28.5	4.0	6.0
B21+	30-60/70	<10	8.8			50.4	30.3	6.4	2.6	2.5	86.0
C/B	60/70-80					30.2	19.9	23.4	10.2	6.0	58.5

• The three profiles shown here represent well the variation over short distances (within farm or paddock) for soils developed on the Moorabool Viaduct formation sediments.
• The texture contrast and the sodic subsoil restricts drainage and the soils readily become waterlogged in winter.
• The sandy topsoils are very susceptible to soil structure decline; the weak aggregation is readily destroyed by cultivation and the soils are prone to compaction. Bare soil is vulnerable to structural breakdown by rain (slaking and sealing) and to erosion by water. In dry conditions these soils are known to be vulnerable to wind erosion.
• Plough pans are common in these soils. Disruption of pans by tillage is short lived unless controlled traffic is deployed in cropping situations. Raised beds have been used with some degree of success in these soils but the unstable topsoils do not lend themselves well to bed survival.

• Two additional sites were excavated in the vicinity.
  SFS19a - Variant with less gravel, thicker and sandier A1+A2 horizon. More prone to wind erosion and waterlogging
  SFS19b - Variant with shallower profile and greater (80%) and coarser (10-40 mm) gravel content