NE26

Site NE26 Landscape

Soil Profile Morphology:

Surface Soil

A1	0-10 cm	Dark brown (7.5YR3/2); fine sandy loam; weak coarse blocky structure; weak consistence moist; contains a few (2%) angular quartz gravels (4 mm diameter); pH 4.8; clear change to:	Site NE26 Profile
A2	10-40 cm	Strong brown (7.5YR5/6) conspicuously bleached (10YR7/4); fine sandy loam becoming light fine sandy clay loam with depth; weak consistence moist; contains a few (5%) angular quartz (5 mm diameter) and schist (60 mm diameter); pH 5.1; clear change to:
Subsoil
B21	40-50 cm	Yellowish red (5YR5/8); fine sandy light clay; moderate medium blocky, parting to moderate fine blocky structure; firm consistence moist; pH 5.4; clear change to:
B22	50-100 cm	Yellowish red (5YR5/6); fine sandy light clay; strong medium blocky, parting to moderate fine blocky structure; contains a few (5%) angular quartz and schist fragments (3-4 mm diameter); pH 5.5:
B3	100-180 cm	Dark red (2.5YR4/8) with reddish yellow (7.5YR6/8) mottles; fine sandy clay loam; contains sandy pockets and mica; pH 5.3.

• Texture contrast between surface (A) horizons and subsoil (B21) horizon.
• Strongly acid subsoil.

Horizon	Horizon Depth (cm)	Exchangeable Aluminium mg/kg	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	110	28	9
A2	10-40	100	18	4	18	53	19	12
B21	40-50	120	26	14	10	35	15	41
B22	50-80	53	36	21
B3	100-180	120

• Plant available water capacity (PAWC) is considered to be medium (estimated at 110 mm). This is based on available laboratory data and assumes an effective rooting depth of 100 cm.

• The surface soil has a high fine sand content which indicates that significant slaking will occur if organic matter levels decline. Organic matter levels are reasonably high at this site.
  
• The surface soil is very strongly acid which indicates that aluminium and manganese toxicity may occur. The level of exchangeable aluminium (110 mg/kg) measured at this pit site is high enough to restrict the growth of aluminium sensitive species e.g. lucerne, phalaris, some medics. A pH/aluminium test on a bulked sample taken from across the paddock would be useful for determining the amount of lime needed to raise soil pH. Other factors that need to be considered before lime is recommended include: pasture species grown, method of application, local trial responses and likely cost/benefit.
  
• Deficiencies in molybdenum, phosphorous and potassium may occur in the very strongly acid surface soil. Lime application may assist in increasing phosphorous availability. Plant tissue analysis could provide a more accurate assessment of molybdenum requirements.
  
• The level of exchangeable aluminium (100 mg/kg) measured in the subsurface (A2) horizon is high similar to the surface (A1) horizon .

• The top of the subsoil is strongly acid and the level of exchangeable aluminium (120 mg/kg) is still likely to affect aluminium sensitive species. Surface liming will have a negligible impact on the pH in the subsoil due to the deepness of the subsoil.