CRC18

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Location: Lexton
Aust. Soil Class.: Vertic (& Magnesic), Mottled-Subnatric, Red SODOSOL (medium to thick very gravelly surface horizons)

General Site Description: Gently undulating rise
Site Description: Pasture
Geology: Cambrian/Ordovician sediments

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

CRC18 Landscape

Soil Profile Morphology:

Surface Soil			CRC18 Profile
A1	0-10 cm	Very dark greyish brown (10YR3/2); fine sandy loam; hardsetting; weak coarse angular blocky, parting to weak medium angular blocky structure; many (25%) fine (2-20 mm) angular and subangular quartz fragments; pH 5.6; clear change to:
A21	10-25 cm	Brown (10YR4/3) conspicuously bleached (10YR7/2 dry); fine sandy loam; massive; very firm consistence (dry); many (50%) fine (2-25 mm) subangular quartz fragments; pH 5.8; clear change to:
A22	25-45 cm	Yellowish brown (10YR5/4) conspicuously bleached (10YR7/2 dry); light sandy clay loam; massive; very firm consistence (dry); very few (<2%) medium to coarse (2-25 mm) ferruginous nodules; very many (50-70%) few to many fine (2-4 mm) quartz fragments; pH 6.2; clear change to:
A23	45-50 cm	Light yellowish brown (2.5Y6/4) and yellowish red (5YR5/6) conspicuously bleached (10YR7/2 dry); coarse sandy clay loam; massive; strong consistence (dry); very few (<2%) medium to coarse (5-20 mm) ferruginous nodules; macropores present; pH 6.1; abrupt and wavy change to:
		Note: in some areas there may only be a surface (A1) horizon overlying clay subsoil at 10 cm depth. In other areas the surface (A1) horizon overlies a bleached (A2) horizon, and the subsoil can be as much as 60 cm from the surface.
Subsoil
B21	50-65 cm	Dark red (2.5YR4/6) with many (20%) medium (5-15 mm) reddish yellow (7.5YR6/8) mottles; light medium clay (superplastic); strong coarse angular blocky, parting to strong medium angular blocky structure; strong consistence (dry); few (1-2%) fine (2-5 mm) quartz fragments; pH 5.9; gradual change to:
B22	65-85 cm	Brownish yellow (10YR6/6) with many (40%) medium (5-15 mm) distinct dark yellowish brown (10YR4/6) mottles; light medium clay; strong consistence (dry); pH 5.4; clear change to:
B23	85-110 cm	Dark yellowish brown (10YR4/6) with distinct light grey (2.5Y7/2) mottles; light medium clay; weak to medium very coarse prismatic, parting to medium very coarse blocky structure; smooth-faced peds; strong consistence (dry); few (2-5%) medium (6-20 mm) angular quartz fragments; slickensides present; gradual change to:
B24	110-140 cm	Dark red (2.5YR4/6) with distinct light grey (2.5Y7/2) mottles; light medium clay (silty); medium coarse polyhedral structure; smooth-faced peds; slickensides present; pH 5.6; pH 5.7; clear change to:
BC	140-150 cm	Light yellowish brown (2.5Y6/3) with reddish yellow (5YR6/6) mottles; light medium clay:
R+	50+ cm	Saprolite

Key Profile Features:

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

Soil Profile Characteristics:

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Moderately Acid	Very Low	Non-Sodic	None¹
Subsoil (B21 horizon)	Moderately Acid	Low	Sodic	Moderate to Complete
Deeper subsoil (at 55-70 cm)	Moderately Acid	Low	Sodic	Strong
¹ Slight dispersion after remoulding

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	0-10	5.6	4.8	0.11		5.3	0.89	0.38	0.27	<10	10	32	-	16	51	14	10
A21	10-25	5.8	4.6	<0.05		0.75	0.19	0.08	0.11	24	3.0	21.7	-	21	55	17	5
A22	25-45	6.2	5.0	<0.05		0.96	0.40	0.10	0.17	<10	-	16.2	-	29	46	12	9
A23	45-50	6.1	4.6	0.05		0.89	1.1	0.11	0.37	54	-	18.9	7.4	21	38	20	19
B21	50-65	5.9	4.8	0.17		2.2	3.8	0.24	1.3	81	11	38.3	22.7	4	16	12	65
B22	65-85	5.4	4.3	0.22		0.71	6.3	0.32	2.6	370	18	47.3	29.2	1	3	6	86
B23	85-110	5.2	4.3	0.25								43.0	25.7	3	1	11	72
B24	110-140	5.6	4.9	0.27		NR	NR	NR	NR					2	5	23	66
BC	140-150	5.7	4.3	0.17		0.14	15	0.30	6.6	400	15			10	7	33	46

Notes:

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

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