GN32

GN32 Landscape

A1	0-10 cm	Brown (10YR4/3); light clay; moderate-strong coarse to medium polyhedral structure; strong consistence (dry); hard surface condition; surface cracking; pH 5.8; abrupt change to:	GN32 Profile
Subsoil
B21	10-35 cm	Greyish brown to brown (10YR5/2 & 5/3) with diffuse yellowish brown (10YR5/6) mottles; medium clay; moderate very coarse prismatic structure; very strong consistence (slightly moist); some dark staining along prism faces; pH 7.3; clear change to:
B22	35-80 cm	Light olive brown (2.5Y5/3); medium heavy clay; strong fine to very fine lenticular structure; firm consistence (moist); few (10%) dark manganese stains in patches; pH 8.6; gradual change to:
B23	80-120 cm	Light olive brown to light yellowish brown (2.5Y5/3 & 6/3); light clay; lenticular structure; weak consistence (moist); pH 8.6; clear change to:
B24	120-150 cm	Light brownish grey (10YR6/2) with very many (50%) yellow and brownish yellow (10YR8/6 & 6/8) mottles; light medium clay; coarse to medium lenticular, parting to strong medium subangular blocky and strong fine to very fine polyhedral structure; manganese stains; pH 8.4.

• Clay texture throughout profile.
• Vertic properties (i.e. as evidenced by lenticular structure)
• Surface cracking when dry.

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	Moderately Acid	Extremely High	Non-Sodic	None
Subsoil (B21 horizon)	Strongly Alkaline	Extremely High	Strongly Sodic	None1
Deeper subsoil (at 120-150 cm)	Moderately Alkaline	Extremely High	Strongly Sodic	Moderate

Horizon	Horizon Depth	pH (water)	pH CaCl2	EC 1:5	Exchangeable Cations
					Ca	Mg	K	Na
					meq/100g
A1	0-10	5.8	5.5	1.6	0.43	4.6	5.8	0.5	0.8
B21	10-35	7.3	7.3	1.5	0.35	6.3	10	0.8	7.2
B22	35-80	8.6	8.6	1.6	0.35	6.3	13	0.9	8.5
B23	80-120	8.6	8.6	1.1	0.21	3.6	9	0.5	5.8
B24	120-150	8.4	7.8		0.20	3.9	9.9	0.6	6.5

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		7.5	28.3	15.1	3	33	2	34
B21	10-35			33.1	16.8	1	21	26	54
B22	35-80			38.4	18.3	1	15	23	57
B23	80-120			31.3	14.5
B24	120-150

Management Considerations;

Whole Profile

• The whole profile has a very high level of soluble salts throughout. This will significantly affect the growth of salt-sensitive species.
• The water table is also likely to rise into the upper soil profile during wet seasons – evidenced by grey and yellow mottling at depth and managnese staining in patches. This will create another constraint to the growth of waterlogging-intolerant species.
• The soil profile displays strong vertic features (i.e. cracking and development of lenticular peds) which indicates that significant shrinking and swelling occurs during wetting and drying cycles.

• The coarsely structure upper subsoil is strongly sodic which will restrict root growth. However, dispersion only occurs after remoulding – due to the effect of the high level of soluble salts restricting dispersion. This is likely to limit the restriction to water movement that such high levels of sodicity would normally impose.