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The effect of Cd pollution (50 mgkg -1 ), with and without sewage sludge (Sw) and phosphate fertiliser (P) addition on soil biochemical activity and available Cd was assessed in a 112 day soil incubation experiment. The availability of Cd decreased with incubation time and was reduced by the sludge and P additions resulting in the following order, Cd>P+Cd>Sw+Cd. With the exception urease and NAGase activities, all other enzyme activities were negatively correlated with available Cd. The total culturable bacterial population was significantly higher with the addition of sewage sludge alone (Sw) than the control during the incubation period (P<0.05). The number of fluorescent pseudomonas decreased with time, but was significantly increased by the addition of sewage sludge. The total fungal populations decreased with time in all treatments, whilst the addition of sewage sludge and phosphate fertilisers increased the fungal population. Addition of sewage sludge in the presence of Cd increased the fungal populations in relation to the addition of Cd alone. The results support the view that Cd contamination has a large detrimental effect on nutrient cycling and microbial activity and the effects of Cd were reduced by P and sewage sludge additions

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