EGC224

Location: Ambyne

Australian Soil Classification: Haplic, Eutrophic, Red CHROMOSOL

Map Unit: Ambyne (Component 1)
Previous Site Name: EG224

General Landscape Description: Rolling hills
Site Description: Simple upper slope 15% south east
Land Use: Grazing
Native Vegetation: Grassy woodland
Geology: Granite


Photo taken about 1.5km north-west of Ambyne Crossing looking south-east along the Deddick River valley


Soil Profile Morphology:

Surface soil
A11	0 – 18 cm	Dark reddish brown (5YR3/3); coarse sandy loam; weak fine granular structure; weak consistence dry; pH 7.2; clear change to:
A12	18 – 40 cm	Yellowish red (5YR4/6); coarse sandy loam; weak medium polyhedral structure; firm consistence dry; pH 7.3; abrupt change to:
Subsoil
B2	40 – 70 cm	Dark red (2.5YR3/6); coarse sandy clay loam; moderate coarse polyhedral structure; strong consistence dry; passing to very weak rock; pH 6.3; diffuse change to:
C	70+	Weak granitic rock becoming more frequent with depth.

• Lack of strong texture contrast between the surface (A) and subsoil (B) horizon.
• Shallow depth to decomposing granite.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC dS/m	Organic Carbon %	Total Nitrogen %	Exchangeable Aluminium ppm	Exchangeable Acididty meq/100g	Exchangeable Cations				Coarse Sand (0.2-2.0 mm) %	Fine Sand (0.02-0.2 mm) %	Silt (0.002-0.02 mm) %	Clay (<0.002 mm) %	Field Capacity % w/w	Wilting Point % w/w
									Ca	Mg	K	Na
									meq/100g
A1	0-18	7.2	6.3	<0.05	1.1	<0.05	<10		4.6	1.3	0.37	<0.05	50	25	9	14	18.3	4.9
A2	18-40	7.3	6.2	<0.05	0.37	<0.05	<10		2	2	0.36	0.064	47	26	11	15	16.6	4.6
B2	40-70	6.3	5.0	<0.05	0.35	<0.05	20	5.4	4.2	4.7	0.37	0.11	40	20	14	22	22.2	9.0

• Plant available water capacity is considered to be low (estimated at 62 mm) for the top 65 cm of the soil profile.
• The low wilting points of each horizon to this depth (4.9, 4.6 and 9.0) indicates plants are able to use light rains when the soil is dry. Due to the low water storage capacity, plants will suffer moisture stress unless further rains occur.

• As mentioned above, the soils surface soils can hold little water, but plants can use light rains following a dry spell.
• The surface soil is slightly alkaline. Here the pH has no adverse implications for plant growth.
• The nutrient holding capacity of the surface horizons is low (based on the sum of the calcium, magnesium, potassium and sodium cations).
• The organic matter content of the surface soil is low. Increasing organic matter will help maintain soil fertility and water holding capacity.
• The potassium is at a moderate level for pastures and no response to added potassium would be expected.

• The slight increase in clay content is unlikely to restrict root penetration of deep rooted species until the decomposing granite is reached at about 70 cm.