NECRC1

Location: Tarrawingee	Australian Soil Classification: Bleached-Mottled, Eutrophic, Red CHROMOSOL
General Landscape Description: Gently undulating rise	Site Description: CRC-PBMDS native grass trial site
Geology: Ordovician marine sediments (metamorphosed) adjacent to Devonian granite

NECRC1 landscape

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Very dark greyish brown (10YR3/2); sandy loam; weak to moderate medium polyhedral structure; many (20%) small to medium (2-15 mm) angular quartz and ferruginous sandstone; few (5-10%) patches of charcoal; pH 5.2; clear change to:	NECRC1 profile
A2e	10-30 cm	Yellowish brown (10YR5/4) conspicuously bleached (5YR7/4 dry); sandy loam; massive; many (25%) small to large pebbles (2-40 mm) (quartz ferruginous sandstone and shale); pH 5.7; sharp and wavy change to:
Subsoil
B21	30-60 cm	Dark red (2.5YR4/6); light medium clay; strong medium to fine polyhedral structure; firm consistence (slightly moist); pH 6.2; gradual change to:
B22	60-90 cm	Dusky red (2.5YR3/4) with strong brown (7.5YR5/6) mottles; medium heavy clay; strong medium to fine polyhedral structure; firm consistence (slightly moist); shiny-faced peds; pH 6.3; gradual change to:
B/C	90-130 cm	Dark bluish grey (5B4/1) with dark reddish brown (5YR3/4) mottles; firm consistence (slightly moist); shiny-faced peds; pH 6.1; gradual and wavy change to:

• Strong texture contrast between surface (A) horizons and subsoil (B21) horizon.

Horizon	Horizon Depth (cm)	Exchangeable Aluminium mg/kg	Exchangeable Acidity	Field Capacity pF 2.5	Wilting Point pF 4.2	Coarse Sand (0.2-2.0 mm)	Fine Sand (0.02-0.2 mm)	Silt (0.002-0.02 mm)	Clay (<0.002 mm)
A1	0-10	80	14	23.9	9.1	21	43	13	16
A2e	10-30	<10	2.3	14.7	2.8	25	53	13	7
B21	30-60	<10	5.5	26.0	15.9	12	28	9	51
B22	60-90	<10	3.8	25.7	13.1	14	37	9	40
B/C	90-130	25	3.8

• The surface soil is strongly acid which indicates that aluminium toxicity may occur. The level of exchangeable aluminium measured in the laboratory is reasonably high (80 mg/kg) and likely to affect aluminium-sensitive species. There should be likely long-term benefits of applying lime, preferably incorporated, at this site (if the results for this pit site are representative of the paddock). Raising surface level pH will help reduce any toxic effects of aluminium. Other factors need to be considered, however, before lime is recommended (e.g. pasture species grown, method of application, local trial responses, soil surface structure and likely cost/benefit). A pH/aluminium test on a bulked sample (from across the paddock) would be appropriate to determine if lime is needed to raise pH.
• Deficiencies in molybdenum, phosphorus and potassium nay occur in strongly acid soil. Lime application may also assist in alleviating molybdenum deficiency and increase phosphorus availability.

• Upper subsoil is non-sodic and well structured (parting strongly to medium to fine polyhedral shaped peds). This indicates that there will be relatively few limitations to root and water movement into the subsoil.