土壤环境因子对毒死蜱两种剂型持效性的影响

Influence of environmental factors on persistence of chlorpyrifos microcapsule suspension and emulsifiable concentrate in soils

以暗黑鳃金龟Holotrichia parallela幼虫为生物试材,研究了含水量、温度和泥炭质量分数3种土壤环境因子对毒死蜱30%微囊悬浮剂(CS)和30%乳油(EC)持效性的影响。结果显示:在相同土壤介质环境下,毒死蜱乳油的持效期随土壤含水量的提高而缩短,同时土壤含水量的提高减缓了微囊悬浮剂囊内有效成分的释放;在土壤中其他影响因子相同时,土壤温度越高,毒死蜱微囊悬浮剂和乳油的持效期越短;土壤中的泥炭对毒死蜱的吸附作用使得其对暗黑鳃金龟幼虫的初始毒力降低,同时也延长了毒死蜱在土壤中的持效期。对于3种土壤环境因子的不同处理,除泥炭质量分数为1.0%的处理中毒死蜱微囊悬浮剂和乳油对暗黑鳃金龟幼虫的持效性相差不大外,其他各处理中毒死蜱微囊悬浮剂的持效性均优于乳油。

Influence of environmental factors on persistence of chlorpyrifos microcapsule suspension（CS） and emulsifiable concentrate（EC） against larva of Holotrichia parallela in soils were studied under ambient conditions using bioassay method.The results indicated that under the same conditions,persistence of chlorpyrifos EC decreased and the release of chlorpyrifos in microcapsules slowed down as soil moisture increased.Persistence of chlorpyrifos CS and EC in soil decreased as soil temperature increased.The active ingredient was trapped by organic soil,so the toxicity of chlorpyrifos CS and EC against H.parallela decreased,however its persistence extended.Among the results of different environmental factors tested,the persistence of chlorpyrifos CS in soil were all better than that of chlorpyrifos EC except when the organic content in soil was 1.0%,which showed that the persistence of chlorpyrifos CS and chlorpyrifos EC was similar.