• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1154-1160
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• 2008

Changes of zinc speciation and dehydrogenase activity in soil were studied before and after a field scale phytoextraction by Fagopyrum esculentum at a paddy soil near a closed zinc mine. The concentrations of zinc in paddy soil, in which Fagopyrum esculentum was planted, ranged from approximately 600 mg/Kg(high Zn soil) to 300 mg/Kg(moderate Zn soil). Despite of severe growth inhibition by Zn at the high Zn region, Fagopyrum esculentum accumulated phytoavailable fraction of Zn absorbed from the soil, and enhanced soil dehydrogenase activity (DHA) that had been inhibited by Zn toxicity. After the plant cultivation of 2 months, the concentrations of phytoavailable Zn in the rhizosphere soil at high and moderate Zn region has decreased 25% and 75%, respectively. The amount of Zn reduction in the rhizosphere soil corresponds to that accumulated in plants (recovery 92$\sim$107%), which implies Fagopyrum esculentum removed Zn from the soil. DHA was inversely correlated to the total Zn concentrations in soil. Before plant cultivation, the DHA in the high Zn soil was twice lower than that in the moderate Zn soil. More than 35% of DHA increase was observed in both soils after the application of phytoextraction with Fagopyrum esculentum.