GL100

Location: Casterton

Australian Soil Classification: Melanic, Subnatric, Brown SODOSOL (confidence level 1)
General Landscape Description: Rises, low hills
Site Description: Upper slope, 10%.
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 Profile Morphology

A1	0-20 cm	Very dark brown (10YR2/2); clay loam; strong very fine subangular blocky structure; very firm consistence, dry; contains very few sedimentary fragments; pH 5.8; changes to:
Subsoil
B21	20-40 cm	Dark brown (10YR3/3); light medium clay; medium to strong medium columnar to subangular blocky structure; very firm consistence, dry; pH 6.2; changes to:
B22	40-60 cm	Dark brown (10YR3/3), with common orange mottles; medium clay; weak to medium subangular blocky structure; very firm consistence, moderately moist; pH 7.3; changes to:
B23	60-80 cm	Brown (10YR4/3), with many light brown mottles; medium heavy clay; weak to medium subangular blocky structure; very firm consistence, moderately moist; pH 8.3; changes to:
B3	80-95 cm	Light olive brown (10YR5/4); fine sandy light clay; very firm consistence, moderately moist; pH 9.1; changes to:
BC	95-105 cm
C	105+ cm

• Alkaline subsoil
• Sodic subsoil
• Mottled subsoil
• Topsoil dispersive when worked when wet
• Top of subsoil dispersive when worked when wet

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
A1	0-20	5.8	4.8	0.14	2.5	0.25	27	16	4.9	5.3	0.84	1.3	2	32	27	34	36.5	18.4
B21	20-40	6.2	4.7	0.11			63	15	3.7	8.2	0.98	3.2	1	25	26	45	39.0	20.6
B22	40-60	7.3	6.1	0.22					6.1	16	1.3	5.6	1	19	21	58	48.2	25.7
B23	60-80	8.3	7.3	0.25					6.9	18	1.2	6.5	1	22	23	54	49.1	28.6
B3	80-95	9.1	8.2	0.39									5	28	29	37	47.4	28.8