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.