Site WW66

Position In Landscape: Swamp.

General Landscape Description:

This unit forms the intermittent swamps that typically dry out in summer to varying degrees. Some swamps totally dry out while others still have signs of a perched watertable close to the surface. This particular soil description was made at the edge of the swamp where the perched watertable recedes over the drier months. The soils developed on the swamp bed is variable, with some swamps having deeper sand deposition over the clay compared with this description.

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Brown (7.5YR5/4) sand; pH 5.5; abrupt transition to:
Subsoil
B21	10-30 cm	Grey (10YR5/1) medium heavy clay (fine sandy); some structure; plastic consistence; some oxidised roots; pH 7.1; diffuse transition to:
B22	30-50 cm	Dark grey; medium heavy clay (fine sandy); little structure; plastic consistence; a few mottles and oxides roots:
B23	50-75 cm	Dark grey; medium heavy clay (fine sandy); structureless; plastic consistence; a few mottles and oxides roots; pH 8.4; clear to gradual boundary to:
B24	75-90+ cm	Grey (10YR6/1); clay (fine sandy); structured; plastic consistence; calcium carbonate is abundant at greater than 90 cm; pH 9.0.

Horizon	pH	Salinity	Sodicity	Dispersion	Internal Drainage	Hydro-phobicity
Surface (A1 horizon)	moderately acid	low	-	-		nil
Subsoil (B21 horizon)	neutral	low	-	-	poorly drained#
Deeper subsoil (at 1 metre)	strongly alkaline	low	-	-

• Acidic topsoil and alkaline subsoil at depth.
• Poorly drained.
• Presence of fine sand in the subsoil may indicate that the subsoil cracks on drying.
• Oxidised roots indicate waterlogging.
• Grey colour of the subsoil indicates that the clay is undergoing anaerobic conditions (lack of oxygen) for many months of the year.
• Calcium carbonate occurring at depth.