Aluminium in the soil - Soil Essentials: Managing Your Farm's Primary Asset - page 59

Table 16 The tolerance of crop and pasture plants to aluminium

(Source: Soil Sense C-07)

Species Level of exchangeable

aluminium above
which yields are
reduced. (Aluminium
percentage of CEC.)

Sensitivity

Lucerne 5 Highly sensitive

Barley
Medics
Canola
Red Clover 10 Sensitive

Phalaris
Sub. Clover
Wheat
Woolly Pod Vetch 20 Moderately tolerant

Rose Clover
Ryegrass
Fodder Rape
Some Oats
Tall Fescue
Cocksfoot
Oats 30 Highly tolerant

Triticale
Cereal Rye
Lupins
Maku Lotus
Note . Within species, varieties can vary significantly in their reaction to
aluminium toxicity. Generally, lucerne should not be sown when subsoil
exchangeable aluminium is greater than 50 milligrams per kilogram, although this
may depend on the cation exchange capacity (CEC) of the soil. There are
interactions between calcium and magnesium in the soil that may allow lucerne to
be grown, even if the exchangeable aluminium levels would seem to preclude the
option. High levels of organic carbon can also reduce the toxic effect of aluminium
on plants (Figure 20 on p. 109).