Effects of Both Single and Combined Pollution of Copper and Glyphosate on Enzyme Activity in Paddy Soil

The effects of both single and combined pollution of Cu and glyphosate on the activities of amylase, urease, phosphatase and cata- lase in paddy soil were studied under laboratory incubation condition. The results showed that there existed significant differences in effects of between single and combined pollution on soil enzyme activity. When the soils were treated with Cu, the activities of amylase, urease and phosphatase were inhibited; the catalase activity was stimulated with low concentration of Cu while inhibited with high concentration of Cu. When the soils were treated with glyphosate, the activities of amylase and urease were stimulated, the activity of catalase was inhibited, and phosphatase activity was stimulated at low concentration of glyphosate while inhibited at high concentration of glyphosate. It was found that there was a significantly interaction between Cu and glyphosate in case of combined pollution. The toxicity effect on catalase activity followed the order of combined pollution of Cu and glyphosateglyphosateCu. The toxicity effects on the activities of amylase, urease and phosphatase followed the order:Cucombined pollution of Cu and glyphosateglyphosate. Analysis of variance also indicated that there were significant differences in soil enzyme activities in the contents of Cu or glyphosate(P0.01). Between the interaction of Cu and glyphosate, the difference of amylase and urease was extremely significant, and the difference of phosphatase and catalase was not significant.