The effects of soluble-Al on root growth and radicle elongation

In order to determine the effects of concentration on plant growth, aluminium (Al) was extracted (10−3M CaCl2) from 4 acid brown hill soils which had been treated with superphosphate at rates equivalent to 0 to 300 kg P ha−1. The soils ranged in pH (CaCl2) from 3.5 to 4.9, and Al concentration from 0 to 0.6 mM. The effects of Al on ryegrass growth in the 4 soils in a glasshouse was compared with its effect on radicle elongation of seeds germinated in contact with CaCl2 extracts from the same soils.