土壤中草甘膦与镉的交互作用对3种土壤酶活性的影响

研究了两种土壤中草甘膦与镉交互作用对土壤三种酶活性的影响．结果发现,低浓度镉略促进乌栅土中的脲酶活性,而高浓度镉则显著抑制了其脲酶活性,当与草甘膦共存时,草甘膦的存在增强了镉对脲酶活性的抑制作用; 镉对红壤中脲酶活性的影响较小,而草甘膦单一或与Cd共存时均显著抑制了红壤中脲酶的活性．镉抑制了乌栅土中酸性和碱性磷酸酶活性,而草甘膦的存在增加了镉的毒性,两者表现为协同作用;低浓度镉促进了红壤酸性磷酸酶活性,而高浓度镉则抑制了土壤酸性磷酸酶活性,草甘膦的存在降低了红壤中镉的毒性,两者表现为颉颃作用．镉对红壤中碱性磷酸酶的活性影响较小．

Effects of Glyphosate and Cd Interaction on the Activities of Several Soil Enzymes

Effects of glyphosate (GPS) and Cd interaction on soil urease and phosphatase activities were studied. Cadmium in a Wushan soil (WS, Anthrosol) slightly promoted and inhibited urease activity when its concentration was lower than 0.1 mmol·kg-1 and higher than 0.5 mmol·kg-1 respectively. When glyphosoate and Cd coexisted in the WS, the inhibition of Cd to urease activity increased. In the red soil (R, Udic Ferrosols), Cd did not affect urease activity, but glyphosate significantly inhibited the activity. Cadmium inhibited the activities of acidic and alkaline phosphatase in the WS, the presence of glyphosate enhanced the inhibition. Low and high concentrations of Cd promoted and inhibited the activities of acidic phosphatase in the R. The presence of glyphosate alleviated the inhibition of Cd. However, Cd did not significantly affected the activities of alkaline phosphatase in the R.