SFS 12

Location: Gnarwarre, South Roxby
Aust. Soil Class.: Calcic, Self-mulching, Brown VERTOSOL

Site Description: SFS field day (Nov 1999) demonstration soil pit.

Soil Profile Morphology:

Surface Soil			SFS 12
O		Very dark greyish brown (10YR 3/2) mottles with greyish brown (10YR 5/2) dry colour; friable (3 - 20 mm):
Ap	0-10 cm	Partially self-mulching; light medium clay; very firm to strong consistence; pH 5.5; sharp change to:
Subsoil
B21tg	30-50 cm	Strong brown (7.5R 4/6) prominent (10-20 mm) with very dark grey (10YR 3/1) mottles and dark grey (10YR 4/1) dry colour and light grey (2.5YR 7/2) distinct (<10 mm); medium clay; very coarse prismatic, parting to fine prismatic to smooth irregular faced blocky structure; pH 6.7; gradual change to:
B22ss	60-80 cm	Dark reddish brown (5YR 4/1) slickensides (>100 mm); light medium clay; becoming darker dark greyish brown (2.5YR 4/2); most moisture at this depth (base of cracks); pH 8.5; gradual change to:
B23g	100-110 cm	Pale red (5YR 6/4) with olive yellow (2.5YR 6/6) mottles; fine to coarse and very occasionally small (10 mm) round CaCo₃ nodules; sandy light clay; effervescence at junction of B22/23; massive (apedal) structure; moist/friable; pH 9.1

Key Profile Features:

Soil Profile Characteristics:

¹ Moderate dispersion after remoulding

Horizon	Horizon Depth (cm)	Exchangeable Aluminium mg/kg	Exchangeable Acidity meq/100g	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	14	12	28.2	15.2	18.4	28.5	15.5	33.5
B21	30-50		8.1	35.1	18.9	14.2	25.5	16.5	40.0
B22	60-80			48.2	25.7	10.2	19.1	15.5	52.5
B23	100-110					15.2	34.6	14.5	35.0

Management Considerations:

Whole Profile

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).

Notes

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