Approximately 1 kg each of the sieved and
preincubated soil samples were distributed into eight
7cm diameter plastic pots labeled A – H. Solutions of
analytical grade (Sigma) Sulphate (SO4
2-) salts each of
zinc (Zn), copper (Cu) and nickel (Ni) dissolved in
200 mL of distilled water were applied to the respective
pots singly and in combinations (Table 2) and
thoroughly mixed by a plastic miniature cement mixer.
Soil Sample, A which received no metal amendment,
served as control.