NE28

Soil Profile Morphology:

Surface Soil

• Gradual increase in clay content down the soil profile.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC 1:5	Exchangeable Aluminium mg/kg	Field Capacity pF 2.5	Wilting Point pF 4.2
A11	0-10	4.8	4.2	0.05	170	31	10
A12	10-40	4.8	4.1	<0.05	190	28	6
B21	40-70	5.5	4.6	<0.05	69	26	9
B22	70-100	5.8	5.1	<0.05		24	17
2A	100+	6.0	5.1	<0.05

• Plant available water capacity (PAWC) is likely to be medium at this site.

• The surface horizons are very strongly acid and as a consequence, the levels of exchangeable aluminium measured at this auger hole site are quite high (> 170 mg/kg). At these levels the growth of a number of aluminium sensitive species would be restricted. A pH/aluminium test on a bulked sample taken from across the paddock would be useful for determining the amount of lime required to raise the soil pH in order to reduce aluminium toxicity. However, other factors need to be considered before lime is recommended e.g. pasture species grown, method of application, local trial responses, likely cost/benefit.
  
• Deficiencies in molybdenum, phosphorus and potassium may occur in the very strongly acid surface soil. Lime application may assist in increasing phosphorus availability. Plant tissue analysis could a more accurate assessment of molybdenum requirements.

• The soil pH increases in the subsoil to 5.5 in water and continues to increase with depth. As a consequence, the level of exchangeable aluminium has significantly decreased.
  

• Lime has not been used.