GL171

Location: Arrarat

Australian Soil Classification: Mottled, Mesotrophic, Brown CHROMOSOL (confidence level 1)
General Landscape Description: Undulating rises
Site Description: Lower slope / footslope (7% slope)
Land Unit: Ararat Marine Siltstone
Geology: Cambrian / Ordovician marine siltstones

General Land Unit Description: The dominant landform of this land unit is dissected undulating rises (represented by this site), although there are some rolling low hills (GL166) and some undulating plains that are mainly at the footslopes of the rises. The major land element is the gentler footslopes of the undulating rises and plains. This site occurs on footslopes of the sedimentary undulating rises east of Ararat. The major soil type found on these slopes tend to be reddish and well structured strong texture contrast soils (Chromosols) (GL171). The topsoil and subsoil can be quite acidic and there may be high aluminium levels in some soils. There is evidence of an occasional bleached horizon. The soils are often quite shallow. The soils on the dissected rolling low hills are generally shallow, although they can be quite well structured and are commonly Sodic Red Chromosols (GL166). Banded sedimentary rock outcrop is common on these soil types, especially on the exposed westerly aspects.
Gully erosion on the plains below these hills and on the drainage depression is quite severe.





Soil Profile Morphology:

Surface Soil
A1	0-15 cm	Dark yellowish brown (10YR3/4), sporadically bleached (10YR7/4d); fine sandy loam; weak medium polyhedral parting to moderate very fine polyhedral structure; very weak consistence dry; many medium angular platy quartz pebbles present; pH 5.0; gradual change to:
Subsoil
B21	15-25 cm	Yellowish red (5YR5/6); medium clay; strong very fine subangular blocky structure; weak consistence , dry; pH 5.5; clear and wavy change to:
B22	25-45 cm	Yellowish red (10YR4/6); heavy clay; strong fine subangular blocky structure; weak consistence, moist; contains many medium angular to angular platy sandstone pebbles; pH 5.7; clear change to:
B23	45-60 cm	Yellowish brown (10YR5/8), with many red (2.5Y4/8) mottles; heavy clay; weak subangular blocky structure; pH 6.4; changes to:
C	60+ cm

• Strongly acid topsoil
• Strongly acid subsoil
• Shallow soil
• Many coarse fragments
• Strong texture contrast between topsoil and subsoil
• Mottled subsoil
• Topsoil 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	0-15	5.0	4.2	<0.05	0	0.07	89	7.3	0.76	0.49	0.16	0.2	8	61	19	11	18.5	5.2
B21	15-25	5.5	4.5	<0.05			170	12	2.2	4.6	0.33	0.35	4	24	20	52	41.2	16.9
B22	25-45	5.7	4.8	0.05			60	12	1.5	8.4	0.58	0.57	1	16	11	71	36.2	23.4
B23	45-60	6.4	5.4	0.06			<10	11	0.49	11	0.87	0.96	1	19	10	69	43.5	25.4