氯噻啉对土壤微生物呼吸的影响

Effects of Pesticide Imidaclothiz on Soil Microbes Respiration

为评价烟碱类杀虫剂氯噻啉对土壤生态环境造成的影响,用直接吸收法测定土壤微生物呼吸强度并计算影响率,比较了氯噻啉质量分数为0.03、0.3、3mg/kg对太湖水稻土和吉林黑土中微生物呼吸的影响。结果表明氯噻啉对2种土壤微生物呼吸活性的变化均呈锯齿型,说明土壤微生物的呼吸活性受抑制和受促进作用交替存在,土壤微生物的呼吸活性因农药的加入而产生了波动。根据《化学农药环境安全评价试验准则》中农药对土壤微生物的毒性等级,0.03mg/kg(常量)氯噻啉对太湖水稻土土壤微生物呼吸作用的抑制率达50%,具高毒性;0.3mg/kg(常量10倍)氯噻啉对吉林黑土土壤微生物呼吸作用的抑制率达50%,为中等毒性。

In order to evaluate effects of imidaclothiz on soil ecosystem, soil respiration was measured using sodium hydroxide （NaOH） absorbing method. Imidaclothiz was added to soil samples （Taihu loam and Jilin clay） at concentration of 0.03, 0.3, 3 mg/kg. The results showed the change curves of microbes activated were saw-shape. It indicated that the effects of respiration were restrained and promoted alternately. Soil microbes respiration activities were risen and fallen because of imidaclothiz. According to the standard of chemical pesticides safety evaluation, the restrained rate of imidaclothiz at concentration of 0.03 mg/kg （routine dosage） was over 50%, the toxicity of imidaclothiz was high for Taihu loam, the restrained rate of imidaclothiz at concentration of 0.3 mg/kg （ten times of routine dosage） was over 50%, the toxicity of imidaclothiz was moderate for Jilin clay.