LWA19

Location: Minyip

Australian Soil Classification: Epicalcareous-Endohypersodic, Epipedal, Black VERTOSOL

General Landscape Description: Level plain.
Site Description: Demonstration site. Bare fallow recently cultivated.

Image: LWA19 Landscape
LWA19 Landscape

Soil Profile Morphology:

Surface Soil			LWA19 profile
A11	0-10 cm	Very dark grey (7.5YR3/1); light-medium clay; moderate medium polyhedral, parting to weak very fine granular structure; weak consistence moderately moist; slightly calcareous; roots are common; pH 8.2; sharp change to:
A12	10-15 cm	Very dark grey (7.5YR3/1); light clay; moderate fine platy, parting to moderate very fine platy structure; weak consistence moderately moist; slightly calcareous; roots are common; pH 8.4; sharp change to:
Subsoil
B21	15-30 cm	Dark brown (7.5YR3/2); medium clay; moderate coarse polyhedral, parting to moderate to weak very fine granular structure; weak consistence moderately moist; moderately calcareous; roots are common; pH 8.6; clear change to:
B22	30-55 cm	Dark brown (7.5YR3/2) with very dark grey (7.5YR3/1) mottles; medium-heavy clay; strong coarse prismatic, parting to strong medium angular blocky structure; very firm consistence dry; fine roots common; pH 8.8; gradual change to:
B23	55-80 cm	Brown (10YR5/3) with yellowish brown (10YR5/4) mottles; medium-heavy clay; strong coarse prismatic, parting to strong coarse angular blocky structure; very strong consistence dry; few (2-10%) soft carbonate and coarse calcareous nodules; pH 9.1; diffuse change to:
B24	80-120 cm	Light yellowish brown (2.5Y6/3) with light olive brown (2.5Y5/3) mottles; medium-heavy clay; moderate coarse prismatic, parting to moderate coarse polyhedral structure; very strong consistence dry; very few (2-10%) soft carbonates and coarse calcareous nodules; pH 9.0; diffuse change to:
B25	120-140 cm	Light yellowish brown (2.5Y6/4) with greyish brown (2.5Y5/2) mottles; medium clay; moderate to strong coarse polyhedral, parting to moderate to strong fine polyhedral structure; strong consistence dry; very few (<2%) soft calcareous segregations; pH 9.4.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A11 horizon)	Moderately Alkaline	Low	Non- Sodic	None ¹
Subsoil (B21 horizon)	Strongly Alkaline	Low	Non- Sodic	None ¹
Deeper Subsoil (at 80-120 cm)	Strongly Alkaline	Moderate - High	Strongly Sodic	Strong

¹ Slight dispersion after remoulding.

The pH in the surface is moderately alkaline. The subsoil is strongly alkaline.

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

The surface is non sodic. The upper subsoil is non sodic, becoming strongly sodic at 1 metre.

The clay content in the profile is high throughout.

Boron levels are relatively low in the upper soil profile and become high below 50 cm depth.

Chemical and Physical Analysis:

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	NaCl %	Exchangeable Cations
						Ca	Mg	K	Na
						meq/100g
A11	0-10	8.2	7.7	0.22		38	5.5	3.5	0.59
A12	10-15	8.4	7.9	0.19		39	6	2.1	1
B21	15-30	8.6	8	0.26	<0.02	27	7.6	1.6	2.1
B22	30-55	8.8	8.1	0.32	<0.02	25	13	1.5	5.1
B23	55-80	9.1	8.3	0.44	<0.02	19	17	1.7	7.2
B24	80-120	9	8.4	0.7	<0.02	16	13	1.7	9.1
B25	120-140	9.4	8.7	1.3	0.2	10	15	2.5	24

Horizon	Horizon Depth (cm)	Boron mg/kg	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)


A11	0-10	2.2	1.3	0.13	41.7	21.2	13	17	21	41
A12	10-15	2.4	0.91	0.085	42.3	21.8	12	17	18	42
B21	15-30	2.8	0.61	0.063	40.7	21.1	17	18	13	45
B22	30-55	6.4			53.2	26.7	11	13	11	59
B23	55-80	16			54.6	27.5	9	12	13	59
B24	80-120	24			51.1	26.1
B25	120-140	27

Profile Described By: Melissa Cann (May 2007).

Page top