CRC17

Location: Lexton

Aust. Soil Class.: Vertic, (& Magnesic), Mottled-Mesonatric, Yellow SODOSOL

General Site Description: Intermediate level terrace
Site Description: Grazing paddock
Geology: Cambrian/Ordovician sediments

Photo: Landscape Photo Bet Bet soil pits 1, 2 and 3

CRC17 Landscape

Soil Profile Morphology:

Surface Soil			CRC17 profile
A1	0-8 cm	Very dark greyish brown (10YR3/2); light sandy clay loam; weak medium-coarse subangular blocky structure; firm consistence (dry); fine (2-10 mm) subangular and angular quartz fragments common (10-20%); pH 6.8; abrupt change to:
A21	8-12 cm	Brown (10YR5/3) sporadically bleached (10YR7/2 dry); light sandy clay loam (medium sand); massive; firm to very firm consistence (dry); many (50%) fine (2-20 mm) subangular and angular quartz fragments; pH 5.9; abrupt and wavy change to:
A22	12-15 cm	Yellowish brown (10YR5/4) conspicuously bleached (10YR8/2 dry); sandy clay loam; massive; very firm consistence (dry); many (>50%) fine (2-10 mm) subangular and angular quartz fragments; abrupt change to:
Subsoil
B1	15-17 cm	Yellowish brown (10YR5/4) with many (20%) distinct medium (5-10 mm) strong brown mottles (7.5YR5/4) mottles; light clay (fine sandy); strong consistence (dry); fine (2-10 mm) fine subangular and angular quartz fragments common (15%); forms capping on prism tops; abrupt change to:
B21	17-40 cm	Reddish yellow (7.5YR6/6) with medium (5-15 mm) faint yellowish red 5YR5/6) mottles common (15%); medium clay; strong very coarse prismatic, parting to moderate coarse prismatic, further parting to moderate very coarse to coarse blocky structure; rigid consistence (dry); slickensides at base; cutans on ped surface (i.e. clay skins); pH 6.5; clear change to:
B22	40-55 cm	Brownish yellow (10YR6/6) with few (10%) reddish yellow (5YR6/6) mottles; light medium clay; strong very coarse prismatic (continuous with above), parting to strong coarse to medium subangular blocky structure; strong consistence (dry); very few (0-2%) fine (2-4 mm) quartz fragments; pH 8.1; clear and wavy change to:
BC	55-70 cm	Light yellowish brown (10YR6/6) with light grey (2.5Y7/1) mottles; silty clay; moderate coarse angular blocky structure; strong to rigid consistence (dry); ‘ghost rock’, smooth; pH 8.5; clear change to:
R+	70+ cm	Saprolite - reddish yellow (7.5YR6/8) and light grey (2.5Y7/1); pH 8.3.

Key Profile Features:

Strong texture contrast between surface (A) horizons and subsoil (B21) horizon.
Vertic properties (i.e. slickensides) in subsoil.

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Slightly Acid	Low-Medium	Non-Sodic	None
Subsoil (B21 horizon)	Slightly Acid	Low	Strongly Sodic	Strong
Deeper subsoil (at 55-70 cm)	Moderately Alkaline	Medium	Strongly Sodic	Moderate-Strong

Horizon	Horizon Depth	pH (water)	pH CaCl2	EC dS/m	NaCl %	Exchangeable Cations				Ex Al mg/kg	Ex Ac meq/100g	Field pF2.5	Wilting Point pF4.2	Coarse Sand (0.2-2.0mm)	Fine Sand (0.02-0.2mm)	Silt (0.002-0.02mm)	Clay (<0.002mm)
						Ca	Mg	K	Na
						meq/100g
A1	0-8	6.8	6.4	0.25		13	2.6	0.43	0.93		7.6	36.9	15.7	18	44	16	11
A21	8-12	5.9	4.7	0.11		1.3	1.5	0.13	0.79		7.4	23.2	6.0	17	51	16	12
B21	17-40	6.5	5.4	0.24		0.95	7.4	0.40	2.9	<10	7.9	37.1	16.1	3	11	14	38
B22	40-55	8.1	7.1	0.47		<0.1	5.5	<0.1	2.7			37.2	6.5	2	11	29	56
BC	55-70	8.5	7.4	0.39	0.06	<0.1	1.9	<0.1	1.1					2	19	38	39
R+	70+	8.3	7.6	0.48	0.10									20	31	38	9

Notes:

Soil profile described by Mark Imhof, David Rees and Doug Crawford, (20/12/04).

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