Study On Activities Of Soil Enzyme Induced By Carbofuran And Cadmium, Chlfonylurea-ethyl And Cadmium Combined Pollution

With the rapid developments of industry and agriculture, soil pesticide and heavy metalpollution becomes increasingly terrible. Pesticide and heavy metal coexist in soil environmentwhich easily leads to pesticide and heavy metal combined pollution. Combined pollutionmakes environmental pollution of soil ecosystem become more and more terrible. Now, studyon activities of soil enzyme induced by pesticide and heavy metal combined pollution is stillfewer.In this article we investigated the effects of carbofuran and cadmium ,chlorimuron-ethyland cadmium single and combined pollution on urease, acid phosphatase, oxido-reductase(catalase), invertase in black soil of northeast area.The dynamic effects of both single andcombined pollution of pesticides and cadmium were determined and investigated. Wecompared difference of effects induced by pesticide-heavy metal single and combinedpollution and determined types of pesticide and heavy metal interaction. Meantime wediscussed mechanism of the interaction and that will supply the scientific soil organismevaluation indices for soil safety in northeast area. The conclusion is that:1.Cadmium(5mg.kg^-1),carbofuran(1,5,10mg.kg^-1)and chlorimuron-ethyl (4.5,15,45μg.kg^-1)single pollution all strongly inhibited the activity of urease and the inhibition was recede first ,then hoist and recede finally. The inhibition of chlorimuron-ethyl single pollution wasstronger at higher concentration.Cadmium(5mg.kg^-1)and carbofuran(1,5,10mg.kg^-1),cadmium(5mg.kg^-1)and chlorimuron-ethyl(4.5,15,45μg.kg^-1)separately combined pollution werealso all strongly inhibited activity of urease and the most strongest inhibition of their's wascadmium and middle-concentration carbofuran combined pollution.2.In our examine condition, cadmium and carbofuran single pollution both mostly inhibitedthe activity of acid phosphatase,however,chlorimuron-ethyl single pollution not only inhibitedbut also activated it.The most effects of cadmium and different carbofuran combined pollutionon acid phosphatase activity were inhibition and the most toxity of this combined pollutionwas cadmium and middle-concentration carbofuran combined pollution.3.Evry single pollution all inhibited the activity of catalase first ,and then activated it .Theeffects of cadmium and different carbofuran combined pollution on catalase took on the samecurrents: the inhibition became strong first and weaken finally.With the differentconcentration compages,the effects of cadmium and chlorimuron-ethyl combined pollutionwere different:The middle concentration compages mostly inhibited catalase but the low andthe high concentration compages mostly activated catalase.4. The effects of cadmium and chlorimuron-ethyl single and combined pollution oninvertase activity kept on inhibition first, then activation and inhibition finally.The effects ofsingle and combined pollution all became stronger as the pesticide concentration becamehigher. Carbofuran and cadmium single and combined pollution mostly activated invertaseactivity.5.There were interaction between pesticide and cadmium combined pollution on the four types soilenzyme. The interaction changed as the kinds of soil enzyme and contamination,and the compages ofdifferent combined pollution changed.6. Compared completely the effects of two combined pullution on activities of soil enzyme,we can summarized the order of soil enzyme responsed to single and combined pollution .Thefirst was urease, then was catalase, acid phosphatase and invertase. Activities of urease wereinhibited by all of pesticide and cadmium single and combined pollution and the interactionbetween pesticide and cadmium was evidence. So urease is advised to be the biotoxical indexof combined pollution in soil.