LP35

LP35 Landscape

Soil Profile Morphology

Surface Soil

A11	0-10 cm	Dark reddish brown (5YR3/4); light fine sandy clay loam; hardsetting surface condition; massive in structure but does fracture; weak consistence dry; contains a few (2-10%) ironstone nodules; pH 6.0; abrupt change to:	LP35 Profile
A12	10-20 cm	Dark brown (7.5YR3/4); fine sandy clay loam; massive; strong consistence dry; contains a few (2-10%) ironstone nodules; pH 5.9; abrupt change to:
A13	20-30 cm	Yellowish red (5YR4/6); fine sandy clay loam; massive; strong consistence dry; contains many (20-50%) ironstone nodules; pH 6.6; abrupt change to:
A2	30-40 cm	Yellowish red (5YR5/6) sporadically bleached; fine sandy clay loam; massive; strong consistence dry; contains many (20-50%) ironstone (semi-hard) nodules; pH 6.9; abrupt change to:
Subsoil
B21	40-60 cm	Yellowish brown (10YR5/6); light medium clay; weak coarse prismatic, breaking down to strong medium blocky structure; strong consistence dry; pH 7.1:
B22	60-95 cm	Yellowish brown (10YR5/4) and brownish yellow (10YR6/8); medium clay; moderate coarse prismatic, breaking down to moderate coarse subangular blocky structure; very strong consistence dry; contains a few dark stains; pH 8.0; clear change to:
B23	95+ cm	Light yellowish brown (10YR6/4) and yellowish red (5YR5/8); light medium clay; moderate coarse prismatic, breaking down to strong fine polyhedral structure; strong consistence dry; contains very many (>50%) dark stains and flecks; pH 9.0.

• Surface soil is hardsetting and has a high fine sand content (41%).
• Strong texture contrast between the surface (A) horizons and the clay (B) subsoil.

	pH	Salinity Rating	Sodicity	Dispersion
Surface (A1 horizon)	moderately acid	very low	non-sodic	slight1
Subsoil (B21 horizon)	slightly alkaline	very low	sodic	strong
Deeper subsoil (at 1 m)	strongly alkaline	very low	__	strong
1 Moderate dispersion with remoulding.

Management Considerations:

Surface (A) Horizons

• The surface horizons combined are relatively deep (i.e. 40 cm) which provide favourable plant rooting conditions in terms of plant available water capacity.
• The overall nutrient status of the surface horizon is moderate and total nitrogen levels appear to be relatively high.
• When dry, the surface soil becomes hard and may be difficult to work. When worked in a dry condition it will become "powdery" and may then be prone to structural degradation from raindrop action. Improving organic matter will help improve surface soil structure.
• The surface soil disperses slightly in water (with moderate dispersion after remoulding). This indicates that mechanical disturbance to this horizon while in a moist condition may result in structural problems such as hardsetting, surface sealing and possible cultivation pan development (at the base of the plough depth).

• The top of the subsoil is sodic and disperses strongly in water. This is likely to result in restricted root and water movement through the subsoil. The sporadically bleached A2 horizon above the subsoil indicates that water movement is being restricted into the B horizon.
• The overall nutrient status of the subsoil is moderate.

• Good faba bean paddock.
• Wheat crop unsuccessful.

• Profile described by Mark Imhof, Paul Rampant and Sonia Thompson (15/2/95)