[Objective] To optimize the conditions for clomazone degradation in contaminated soils by degrading bacteria W2. [Method] Three factors affecting degradation rate were studied, including the soil moisture content,the amount of inoculation and fertilizer used. Based on the bioassay method, the degradation rates of bacteria W2 under different conditions were compared by using orthogonally rotational combination design. [Result] Mathematical regression model for clomazone degradation was established as follows: y= 62. 363 9 + 5. 872 8 × C1 —4.494 1 × C2 C3 — 1.262 1× C12 —4. 076 7 × C22. The results demonstrated that the significance order affecting degradation rate was: the soil moisture content, the amount of fertilize used and the amount of inoculation. [Conclusion] When the amount of inoculation ranged from 8.19 mL/kg to 11.81 mL/kg, soil moisture content ranged from 18.6％ to 20.84％, and the amount of fertilizer used ranged from 1.83 g/kg to 2.52 g/kg, the degradation rate was above 60％ in air-dried soils containing 500 μg/kg clomazone after 30 days, close to the highest degradation rate 65.56％.%[目的]确定降解菌W2对土壤中异噁草酮的最优生物修复条件.[方法]采用3因素5水平正交旋转组合设计,室外盆栽生物测定方法,研究降解菌W2接种量、土壤含水量和肥料添加量3种田间可控因子对降解菌W2修复异噁草酮污染土壤效果的影响.[结果]确定修复条件的优化数学回归模型为:y=62.3639+5.8728×C1-4.4941×C2C3-1.2621×C(2)1-4.0767×C(2)2,不同因子对土壤修复影响大小顺序依次为土壤含水量、肥料添加量、降解菌W2接种量.[结论]降解菌W2对土壤中异噁草酮的最优生物修复条件为:降解菌W2接种量8.19～11.81mL/㎏(A650=0.4),土壤含水量18.6%～20.84%,肥料添加量1.83～2.52g/㎏.在此范围内降解菌W2对异噁草酮有效成分浓度为500μg/㎏的风干土壤30d后的降解率可达60%以上,可接近该修复天数的理论极值65.56%.
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