GL9

Location: Warrock

Australian Soil Classification: Vertic, Eutrophic, Brown CHROMOSOL (confidence level 1)
General Landscape Description: Undulating rises
Site Description: Upper slope, 5%
Land Unit: Merino Tablelands
Geology: Cretaceous non-marine sandstone

General Land Unit Description: This unit consists of the Cretaceous non-marine sandstone of the dissected Merino Tablelands. The tablelands were thought to have formed under swamp conditions and a warm climate. As a result, the soils tend to be high in clay and there tends to be carbon rich seams of charcoal deposits at depth in some of the profiles. The main soil type used to represent this land unit is black cracking clays (Vertosols) that can be sodic at depth. This soil type, along with Black Sodosols, Chromosols and Dermosols, are commonly found on the broad crests or drainage lines. The slopes often consist of Brown Chromosols, Sodosols or Dermosols, although black soils can also occur on the slopes. The lower slopes commonly have Grey Vertosols or Sodosols as the major soil type. The reasonably deep sodic soils on short steep slopes tend to be prone to landslips. The grey soils, in particular are prone to water erosion.

Soil pit GL9 landscape

Soil Profile Morphology

A11	0-15 cm	Very dark brown (10YR2/2); organic loam; strong very fine subangular blocky structure; firm consistence, dry; pH 5.5; changes to:
A12	15-45 cm	Black (10YR2/1); organic clay loam; weak structure; firm consistence, dry; pH 5.8; clear change to:
Subsoil
B1	45-65 cm	Very dark grey (10YR3/1); light clay, massive structure; very firm consistence, dry; pH 6.2; clear change to:
B21	65-85 cm	Very dark greyish brown (10YR3/2), sporadically bleached (10YR6/2d), with a few oxidised root mottles; light medium clay; moderate medium prismatic parting to fine subangular blocky structure; strong consistence, dry; pH 6.6; clear change to:
B22	85-115 cm	Very dark greyish brown (10YR3/2); fine sandy loam; moderate subangular blocky structure; strong consistence, dry; sand veins and organic staining present; pH 6.9; clear change to:
B3	115-180 cm	Fine sandy clay loam; moderate fine prismatic to subangular blocky structure; very strong consistence, dry; contains abundant ferromanganiferous concretions; sand veins and organic staining present; pH 6.8.

Key profile features:

Ferromanganiferous pan at depth
Acidic topsoil
Subsoil cracks
Deeper topsoil dispersive when worked when wet
Subsoil dispersive when worked when wet

Soil Profile Characteristics:

-	pH	Salinity	Sodicity	Dispersion
Surface Soil (A11 horizon)	Strongly Acid	Medium	Non-Sodic	None¹
Subsoil (45-65 cm)	Slightly Acid	Low	Non-Sodic	None¹
Deeper Subsoil (115-180 cm)	Slightly Acid	Low	Non-Sodic	None

¹ Complete dispersion after remoulding (20 hrs).

Soil pit GL9 graphs

Chemical and Physical Analysis:

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	Organic Carbon %	Total Nitrogen %	Exchangeable Aluminium ppm	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
									Ca	Mg	K	Na
									meq/100g
A11	0-15	5.5	4.9	0.29	4.6	0.48	<10	19	9.4	5.0	1.6	0.6	2	35	24	27	38.5	19.0
A12	15-45	5.8	4.9	0.14			<10	16	8.8	3.9	0.74	0.99	1	42	25	27	31.8	14.2
B1	45-65	6.2	5.2	0.10			<10	7.5	5.3	3.0	0.40	0.72	1	45	29	22	25.8	9.8
B21	65-85	6.6	5.6	0.12				9.8	10	8.1	0.78	1.3	1	33	20	44	36.1	20.3
B22	85-115	6.9	5.8	0.10				8.0	11	8.1	0.61	1.1	1	58	15	22	31.0	14.6
B3	115-180	6.8	6.0	0.17				7.2	14	9.0	0.59	1.5	3	48	21	25	33.5	16.8

Profile Described By: Natalie Baxter and Grant Boyle, 1st October 2000.

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