LP121

LP121 Landscape

Soil Profile Morphology

Surface Soil

A1	0-15 cm	Dark brown (7.5YR3/4), loamy sand; firm consistence when moderately moist; pH 5.7; clear change to:	LP121 Profile
A2	15-35 cm	Dark reddish brown (5YR3/4), loamy sand; strong consistence when moderately moist; pH 6.4; abrupt change to:
Subsoil
B21	35-55 cm	Reddish brown (5YR4/4), medium clay; weak coarse prismatic structure, breaking to strong medium sized blocky structure; strong consistence when moderately moist; pH 7.5; clear change to:
B22	55-75 cm	Yellowish red (5YR4/6) with strong brown (7.5YR5/6) and yellowish brown (10YR5/6) mottles, light medium clay; weak coarse polyhedral structure, breaking to moderate fine polyhedral structure; strong consistence when moderately moist; few (5%) hard carbonate nodules (up to 50 mm); pH 8.6; gradual change to:
B23	75-100 cm	Yellowish brown (10YR5/8) with reddish brown (5YR4/4) mottle, light medium clay; weak coarse polyhedral structure, breaking to moderate fine polyhedral structure; strong consistence when moderately moist; few (3%) hard carbonate nodules(up to 50 mm); pH 8.7; gradual change to:
B24	100-130 cm	Strong brown (7.5YR4/6), light medium clay; moderate medium sized prismatic structure, breaking to weak medium sized polyhedral structure; trace of carbonate; pH 8.9.

• Strong texture contrast between surface (A) horizon and subsurface (B) horizons

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	moderately acid	very low	non-sodic	none
Subsoil (B21 horizon)	slightly alkaline	very low	non-sodic	slight 1
Deeper subsoil (at 100-130 cm)	strongly alkaline	low	strongly sodic	moderate 1
1 Strong dispersion when remoulded.

Management Considerations:

Surface (A) Horizons

• The surface horizons have a low inherent fertility (based on the sum of the basic exchangeable cations).
• The surface horizons have a low wilting point. This implies that after only a small amount of rainfall there will be moisture available for plant uptake.
• Organic carbon levels show that organic matter content is low for the surface soil from this pit. Organic matter is important for enhancing soil aggregation, fertility and water holding capacity. Organic matter levels will build up under pasture but will decline if cultivation takes place. Practices such as residue retention, minimum tillage and including pasture rotations should be utilised if cropping occurs.

• Most of the subsoil (all below 55 cm) is sodic and dispersive which will result in restricted root and water movement in the soil. The upper subsoil should be relatively good for water and root penetration (ie. non-sodic and well structured) compared to most other sites.
• The deeper subsoil (from 55 cm depth) is strongly alkaline which indicates that some nutrients (eg. copper, iron, manganese, and zinc) may be poorly available to deeper rooted plants.

• Profile described by Paul Rampant and Ruth Lourey (23/5/96)