Effects of Sulfamonomethoxine on Soil Respiration and Enzyme Activity

The animal excrements containing veterinary drugs manured into field soils would result in agricultural soil pollution,and which drew an important potential threat on the human health and ecosystem. The effects of sulfamonomethoxine on soil respiration and enzyme activity were studied in the yellow moist soil by indoor cultivating to evaluate the potential toxicological effects of veterinary drugs. The results showed that soil respiration was influenced obviously under the stress of sulfamonomethoxine,the inhibition rate and activation rate reached 72% and 254%,respectively. The effect on enzyme activity by sulfamonomethoxine was much less than the soil respiration,which demonstrated the fact that soil respiration was much more sensitive under the stress of the drug. Sulfamonomethoxine had inhibition or activation effect on the activities of the tested soil enzymes. Urease activity was inhibited before the 11th day of the test time; Invertase activity was inhitited and stimulated significantly,the ratio reached 18% and 30%,respectively. While catalase activity and phosphatase activity in soil were maily activated,the maximal activation rates reached 17% and 25%,respectively,under the stress of the drug; In addition,the activities of soil res-piration and the four tested soil enzymes fluctuated with time.