LP10

LP10 Landscape

Soil Profile Morphology

Surface Soil

A1	0-10 cm	Dark greyish brown (10YR3/2); heavy clay loam; moderate coarse blocky structure; strong consistence dry; contains a few (2-10%) vesicular pumice fragments; pH 6.3; sharp and wavy change to:	LP10 Profile
Subsoil
B21	10-50 cm	Dark greyish brown (10YR4/2); heavy clay; moderate coarse prismatic, breaking down to strong coarse blocky structure; very strong consistence dry; pH 7.4; gradual and wavy change to:
B22k	50-120 cm	Greyish brown (10YR5/2); heavy clay; strong medium to coarse blocky structure; firm consistence moist; contains a few (2-10%) soft carbonate nodules; pH 9.0; sharp change to:
B23	120-180 cm	Light brownish grey (10YR6/2) and brownish yellow (10YR6/6) mottles; heavy clay; strong coarse lenticular, breaking down to finer lenticular structure; contains a few (2-10%) carbonate nodules and soft carbonate;0pH 8.8; sharp change to:
B3	180+ cm	Very dark grey (10YR3/1); medium heavy clay; strong lenticular structure (with smooth faced peds); pH 8.7.

• Strong textural contrast between surface A horizon (31% clay) and subsoil B horizon (57% clay).
• Sodic subsoil.

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	slightly acid	very low	non-sodic	water-stable1
Subsoil (B21 horizon)	slightly alkaline	very low	sodic	slight-moderate
Deeper subsoil (at 1 m)	strongly alkaline	low	strongly sodic	_
1 Slight to moderate dispersion occurs after remoulding.

Horizon	Horizon Depth	pH (water)	pH CaCl2	EC 1:5	NaCl	Exchangeable Cations
						Ca	Mg	K	Na
						meq/100g
A1	0-10	6.3	5.4	0.08		7.6	4.2	1.2	0.3
B21	10-50	7.4	6.2	0.08		13	11.8	1.5	2
B22k	50-120	9	8.2	0.4	<0.05	15	21.4	1.3	6.6
B23	120-180	8.8	8.1	0.34	<0.05	13.5	24	1.4	10.1
B3	180+	8.7	7.8	0.26	<0.05	10.6	17.8	1	6.8

Horizon	Horizon Depth	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)
A1	0-10			32.1	19.1	7	30	28	31
B21	10-50			44.3	32.7	4	18	19	57
B22k	50-120
B23	120-180
B3	180+

• The surface horizon has a moderate overall nutrient status. Organic carbon and total nitrogen levels are reasonable.
• Although non-sodic, the subsoil may disperse when cultivated or overstocked in a moist to wet condition (as is evidenced by moderate dispersion occurring after remoulding). This could lead to some structural degradation (eg. surface sealing) occurring.

• The coarsely structured subsoil is sodic (becoming strongly sodic with increasing depth) which will restrict root and water movement throughout. The presence of rusty root channel mottling in the surface horizon suggests that water movement is restricted.
• The deeper subsoil (from 50 cm) becomes strongly alkaline which may limit the availability of certain plant nutrients (e.g. phosphorous, iron, manganese and zinc).
• The deep subsoil is vertic (i.e. exhibits a significant degree of shrinking and swelling on wetting and drying) which would have implications for building foundations etc.