Effect of compound pollution of heavy metals on soil enzymic activities
重金属Cd、Zn、Pb复合污染对土壤酶活性的影响

Pot experiment was conducted to study effects of Cd-Zn-Pb compound pollution on four soil enzymic activities(urease, calatase,alkaline phosphatase and intertase)in medium loam meadow cinnamon soil1 The results showed that the inhibiting effect of the three heavy metals on four soil enzymes had a toxicity order:Cd>Zn>Pb meanwhile,influence of Cd-Zn-Pb complex pollu-tion on four soil enzymic activities was very different. The compound pollution of Cd-Zn-Pb on urease activity exhibited synergistic inhibiting negative effect activit y,white on calatasse activit y exhibited protective effect to some extent. Under combination of Cd-Zn-Pb,mainly with increasing Cd contents,intertase and phosphatase activities decreased significantly 1There is a very significant negative correlation between urease and ionic implusion,so it is feasible to use soil urease activit y as primary biochemical index to evaluate Cd-Zn-Pb compound pollution.