SFS12

Location: Mt Pollock

Australian Soil Classification: Calcic, Self-Mulching, Brown VERTOSOL

Site Description: Southern Farm Systems (SFS) field day raised bed demonstration site.
Land Use: Canola crop.


SFS12 Landscape. Also shows the Map Units within the Gnarwarre SFS trial site (Adcock, 1998).

Soil Profile Morphology:

Surface Soil			SFS12 Profile
Ap	0-20 cm	Very dark greyish brown (10YR3/2); self-mulching surface condition; light medium clay; fine to medium friable structure; very firm to strong consistence dry; pH 5.5; sharp change to:
Subsoil
B21tg	20-30/60 cm	Very dark grey (10YR3/1) with prominent common strong brown (7.5YR4/6) mottles as well as distinct common light grey (2.5Y7/2) and yellow (2.5Y7/6) mottles; medium heavy clay; very coarse prismatic, parting to fine prismatic, parting to blocky structure; irregular smooth faced peds; pH 6.7; gradual and irregular change to:
B22ss	30/60-90 cm	Dark grey (5Y4/1) becoming dark greyish brown (2.5Y4/2); light medium clay; coarse slickensides evident; pH 8.5; gradual change to: NOTE: most moisture is at this depth (base of cracks).
B23g	90-130 cm	Pale olive (5Y6/4) with fine to coarse olive yellow (2.5Y6/6) mottles; sandy light clay; massive apedal structure; friable consistence moist; very few coarse calcium carbonate concretions; slight effervescence at B22/B23 junction; pH 9.1.

• Clay texture throughout soil profile.
• Significant shrinking and swelling occurs during wetting and drying cycles.
• Strong cracking when profile dries.

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

The salinity rating is low to medium in the surface and upper subsoil, becoming medium to high in the deeper subsoil.

The surface is non sodic. The subsoil is sodic becoming strongly sodic with depth.

The clay content is moderate throughout the profile.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC dS/m	NaCl %	Exchangeable Cations
						Ca	Mg	K	Na
						meq/100g
Ap	0-20	5.5	4.9	0.20		7.0	5.6	0.43	0.92
B21	20-30/60	6.7	5.7	0.25		5.5	7.9	0.66	3.3
B22	30/60-90	8.5	7.9	0.67	0.09	6.7	11	0.6	6.5
B23	90-130	9.1	8.3	0.56	0.08	4.9	9.6	0.3	6.4

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	0-20	14	12	1.6	0.15	28.2	15.2	18	29	16	34
B21	20-30/60		8.1			35.1	18.9	14	26	17	40
B22	30/60-90	<5				48.2	25.7	10	19	16	53
B23	90-130							15	35	15	35

• Plant available water capacity (PAWC) is considered to be low (estimated at 61 mm) in the upper 50 cm of this soil profile. Effective rooting depth (ERD) is restricted to 50 cm due to the highly sodic subsoils (ESP>20).