LWA10

Australian Soil Classification: Vertic (and Bleached-Ferric), Red CHROMOSOL

Soil Profile Morphology:

Surface Soil

Ap	0-6 cm	Brown (7.5YR4/2); heavy sandy loam; moist consistence; pH 5.6; clear change to:	LWA10 Profile
A12	6-15 cm	Brown (7.5YR4/3); light sandy clay loam; pH 4.6; clear change to:
A21	15-25 cm	Brown (7.5YR4/4); firm to very firm consistence (dry); very many (50 - 90%) ferro-manganiferous concretions (2 – 8 mm); pH 4.7; gradual change to:
A22	25-45 cm	Brown (7.5YR5/4) with pink (7.5YR8/3) mottles; very many (80%) ferro-manganiferous concretions; pH 5.5; clear change to:
Subsoil
B2	45-65 cm	Yellowish red (5YR4/6) with light reddish brown (2.5YR6/4) and reddish brown (2.5YR4/6) mottles; medium clay; moderate coarse (50-100 mm) prismatic, parting to strong medium to fine (5-20 mm) polyhedral structure; firm to very firm consistence (dry); pH 5.9; clear change to:
2B2	65-80 cm	Brown (10YR5/3) with strong brown (7.5YR5/8) and white (10YR8/1) mottles; light clay (fine sandy); strong consistence (dry); many (40%) ferro-manganiferous nodules (2-5m); slight manganese staining; pH 6.6; clear change to:
3B2	80-105 cm	Light yellowish brown (2.5Y6/3) with strong brown (7.5YR5/8), greyish brown (2.5Y5/2) and yellowish red (5YR4/6) mottles; heavy clay; strong coarse (50-100 mm) prismatic, parting to strong coarse (20-50 mm), further parting to coarse (20-50 mm) lenticular structure; firm to strong consistence (dry); shiny ped faces; manganese staining common (20%); pH 8.1; gradual change to:
4B2	105-130+ cm	Light yellowish brown (2.5Y6/3) with yellowish red (5YR5/6) mottles; medium clay; moderate fine (10-20 mm) prismatic structure; firm to very firm consistence (moist); few (5%) manganese staining; few (2%) ferro-manganiferous nodules (5-10 mm); pH 8.6.

Key Profile Features:

Strong texture contrast between surface (A) horizons and subsoil (B2) horizon.

Soil Profile Characteristics:

-	pH	Salinity	Sodicity	Dispersion
Surface Soil (A1 horizon)	Moderately Acid	Low	Non-Sodic	None¹
Subsoil (B2 Horizon)	Moderately Acid	Very Low	Sodic	None
Deeper Subsoil (108-130 cm)	Strongly Alkaline	Very Low	Strongly Sodic	Strong

¹ Slight dispersion after remoulding

South West Gasp Pipeline LWA Graphs

Chemical and Physical Analysis:

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	NaCl %	Organic Carbon %	Total Nitrogen %	Exchangeable Acididty meq/100g	Exchangeable Cations				Coarse Sand (0.2-2.0 mm) %	Fine Sand (0.02-0.2 mm) %	Silt (0.002-0.02 mm) %	Clay (<0.002 mm) %	Field Capacity % w/w	Wilting Point % w/w
									Exchangeable Cations
									Ca	Mg	K	Na
									meq/100g
Ap	0-6	5.6	5.4	0.29	3.0	4.4	0.19	9	4.9	1.0	0.8	0.1	22	42	16	16	24.3	7.2
A12	6-15	4.6	4.3	0.17	1.9	2.4	0.10	9	1.3	0.53	0.86	0.19	24	42	11	19	22.6	6.2
A21	15-25	4.7	4.3	0.13				8	0.68	0.36	0.71	0.21	31	39	12	16	19.7	6.2
A22	25-45	5.5	5.1	0.12				6	1.6	0.68	0.58	0.29	35	34	12	18	20.3	7.6
B2	45-65	5.9	5.2	0.19				13	3.9	6.5	1.4	1.8	3	11	7	79	51.9	28.2
B3	65-80	6.6	5.6	0.10				4	1.6	3.6	0.70	1.5	13	39	16	29	28.1	10.6
B4	80-105	8.1	6.8	0.23					5.8	13	2.3	6.8	3	7	4	84	55.8	31.5
B5	105-130+	8.6	7.6	0.18					4.9	11	1.6	5.5	12	26	7	51	38.5	20.6

Page top