乐果对土壤中酶活性和微生物数量的影响

农药对土壤微生物及酶活性的影响，已成为不少国家评价农药使用安全性的重要指标，该文就乐果对土壤中酶活性及微生物数量的影响进行了初步研究。结果表明，乐果对土壤中酸性磷酸酶的影响较大，中性磷酸酶受影响小些；脱氢酶的变化趋势虽与酸性磷酸酶相仿，而受影响程度更大些；乐果对土壤微生物数量的变化影响不大。总之，乐果对土壤微生物及酶活性有一定抑制作用，但恢复较快，这有利于乐果在土壤中的降解。

Effect of Dimethoate on the Activities of Enzymes and the Amount of Microorganisms in Soil

The influence of pesticides on the activities of microorganisms and enzymes in soil was considered as a safly pesticides, and has been used in many countries. This paper studied the effect of dimethoate on the activities of microorganisms and enzymes in soil. The results showed that the effect of dimethoate on acid phosphatase activity was greater than that on neutral phosphatase activity, but slighter than that on dehyodrogenase activity, and that the effect on the amount of microorganisms was slight. In short, dimethoate has some poisonous effects on the activities of enzymes and microorganisms in soil, but the influence may be reduced in a rapid rate, which may accelerate dimethoate metabolism in soil.