NE37b

NE37b Landscape

Surface Soil

A1	0-10 cm	Brown (10YR4/3); light clay; rusty root channel mottling present; moderate medium polyhedral structure; contains very few (< 2%) manganese nodules (5-10 mm size); pH 5.9;	NE37b Profile
Subsoil
B21	10-25 cm	Brownish yellow (10YR6/6) with strong brown (7.5YR5/8) diffuse mottles; light medium clay; moderate medium polyhedral, breaking to strong fine polyhedral structure; contains a very few (1-2 %) ferromanganiferous nodules (2-5 mm size) [with many (up to 25%) ferromanganiferous and manganiferous nodules and a trace (< 2%) amount of quartz (2-4 mm size) gravel on the flanks of the puffs]; pH 6.3; clear change to:
B22	25-90 cm	Light brown (10YR6/3) with reddish yellow (10YR7/6) and dark red (2.5YR4/8) mottles; medium clay; moderate very coarse prismatic, breaking to moderate coarse blocky structure; contains very few (2 %) ferromanganiferous nodules (2-4 mm size); pH 6.3; wavy change to:
B23	90-100 cm	Light brownish grey (10YR6/2) with brownish yellow (10YR6/8) mottles; heavy clay; rigid consistence dry; contains a few (5-10 %) manganese stains and very few (2 %) ferromanganiferous nodules; pH 7.9;
B24	120+ cm	Greyish brown (10YR5/2); heavy clay.

Key Profile Features:

• Clay texture throughout profile.
• Vertic properties.

	The surface horizon is moderately acid. The upper subsoil is slightly acid and the deeper subsoil becomes alkaline.		Soluble salt levels are very low in the top metre of the soil profile. Levels become low below 1 metre depth.
	The surface soil is non-sodic. The upper subsoil is sodic and the deep subsoil is strongly sodic.		The clay content is high in the surface soil and increases in the upper subsoil.

Management Considerations:

Whole Profile

• Plant available water capacity (PAWC) is considered to be medium (estimated at 130 mm) for the upper 90 cm of this soil profile. Effective rooting depth will, however, be restricted by the dense sodic subsoil below 25 cm depth. Plant available water capacity for the upper 25 cm of the soil profile is 45 mm.
• The soil profile displays strong vertic properties which indicates that significant shrinking and swelling occurs in wetting and drying cycles.

• The surface soil has a moderate inherent fertility (based on the sum of the exchangeable basic cations).
• The wilting point value (ie. 12%) is higher than for any other site in this study. Plants at this site will therefore be relatively less able to utilise light rains when the soil is reasonably dry.
• Tillage of clayey soils such as these should be avoided if the soil is in a moist-wet condition (ie. wetter than the plastic limit). At such moisture conditions, tillage or excessive trafficking or overstocking can result in structural damage (eg. compaction, smearing) occurring. Ideally, tillage and trafficking should take place on clay soils when the soil is drier than the plastic limit, down to at least the tillage depth. [see Appendix A for information on clay compaction and plastic limit].

• The upper subsoil is marginally sodic but does not disperse. It is well structured, breaking into medium to fine polyhedral peds. Root movement will be relatively unrestricted as a consequence.
• The deeper subsoil is sodic, dense and coarsely structured. This will result in restricted root and water movement.