TOPCROP12

Location: Lubeck

Australian Soil Classification: Vertic (& Hypercalcic), Mottled-Subnatric, Brown and Yellow SODOSOLS

General Landscape Description: Gently undulating plain.
Site Description: Midslope of a low rise. Cropping paddock.
Geology: Quaternary (Woorinen Formation) deposits overlying Tertiary (Parilla Sandstone).

TOPCROP12 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Dark grey (10YR4/1); hardsetting surface condition; sandy clay loam; moderate coarse sub-angular blocky structure; weak consistence moist; pH 5.8; clear change to:	TOPCROP12 Profile
Subsoil
B1	10-15 cm	Grey (10YR5/1) with rusty root channel mottling; light medium clay (sandy); pH 6.5; clear, wavy and discontinuous change to:
B21	15-30 cm	Brown (10YR5/3) with many (40%) reddish yellow (7.5YR6/6) mottles; medium heavy clay; moderate-strong lenticular structure; firm consistence moist; sand along vertical crack faces; pH 7.1; gradual and wavy change to:
B22	30-60 cm	Strong brown (7.5YR5/6); heavy clay; strong coarse angular blocky structure; slickensides present; sand along vertical crack faces; very strong consistence dry; few soft and hard carbonates; moderately calcareous; pH 8.9; gradual change to:
B23	60-80 cm	Light brownish grey (10YR6/2) and pale brown (10YR6/3) with few (5-10%) red (2.5YR5/8) mottles; medium clay (sandy); moderate coarse prismatic structure; very many (10-50%) fine-earth carbonates; pH 9.4:
B24	80-100 cm	Pale brown (10YR6/3) with faint brownish yellow (10YR6/6) mottles; medium clay (sandy); fine earth carbonates with many coarse (5-20 mm in size) calcareous nodules common; dark manganese staining (5-10%) common; ferruginised sandstone fragments; pH 9.4:
B25	100-120 cm	Medium clay (sandy); pH9.2.

TOPCROP12 Profile variation.

In some areas the subsoil (B21) is light brown (7.5YR6/4) with pale brown (10YR6/3) mottles. This is underlied by (B22) yellowish red (5YR5/6) clay with large amounts of fine-earth carbonates.

Soil Profile Characteristics:

-	pH	Salinity	Sodicity	Dispersion
Surface (A1 horizon)	Moderately Acid	Low	None	None¹
Subsoil (B21 horizon)	Slightly Acid	Low-Moderate	None	None¹
Deeper Subsoil (at 1 metre)	Very Strongly Alkaline	High	Strongly Sodic	Strong

¹ Slight dispersion after remoulding.
Image: TOPCROP12 graphs

The surface soil is moderately acid. The upper subsoil is slightly acid becoming very strongly alkaline with depth.

The salinity rating is low in the surface. The subsoil is low to moderate becoming high in the deeper subsoil.

The surface and upper subsoil is non-sodic. The deeper subsoil is strongly sodic.

Boron levels increase with depth but are relatively low.

The clay content is moderate throughout the profile.

Chemical and Physical Analysis:

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	Sodium Chloride %	Exchangeable Cations
						Ca	Mg	K	Na
						meq/100g
A1	0-10	5.8	5.4	0.27	0.01	8.4	2.9	0.5	<0.1
B1	10-15	6.5	6	0.3	0.01	7.8	6.8	0.4	0.5
B21	15-30	7.1	6.5	0.44	0.01	14	15	1	3.2
B22	30-60	8.9	8.2	0.41	0.012	11	16	0.9	5.2
B23	60-80	9.4	8.6	0.53	0.04	5.9	12	0.7	5.6
B24	80-100	9.4	8.6	0.76	0.08	5.7	15	0.8	8
B25	100-120	9.2	8.5	0.9	0.12	4.8	14	0.8	8.1

Horizon	Horizon Depth (cm)	Boron mg/kg	Organic Carbon %	Exchangeable Aluminium mg/kg	Total Nitrogen %	Oxidisable Organic Carbon %	Field Capacity pF2.5	Wilting Point pF4.2	Coarse Sand (0.2-2.0 mm) %	Fine Sand (0.02-0.2 mm) %	Silt (0.002-0.02 mm) %	Clay (<0.002 mm) %


A1	0-10	1.4	1.4	11	0.17	2.1	26	11.7	27	36	12	28
B1	10-15	1.5	1.5	9		0.76	28.6	12.5	27	34	7	30
B21	15-30	2.8	2.8			0.49	38.6	19	20	25	7	45
B22	30-60	4.8	4.8			<0.3	38.8	18.5	19	29	6	44
B23	60-80	4.9	4.9			<0.3	35.1	16	21	28	9	29
B24	80-100					<0.3	38.4	17
B25	100-120

NOTES: Gypsum applied to paddock.

Profile Described By: Mark Imhof (July 2007).

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