Abstract:

【Objective】 For optimization of clomazone degradation in contaminated soil by degrading bacteria Y1, three factors affecting degradation rate including field moisture capacity, the amount of inoculum and fertilizer used were studied. 【Method】 Based on the bioassay method , the degradation rates of bacteria Y1 under different conditions were compared by using orthogonally rotational combination design. 【Result】 A mathematical regression model for clomazone degradation was established, that is, y= 65.05812+9.60065*C1+10.49792*C2+3.60229*C3-6.88851*C12-4.41187*C22. Results indicated that the order of significance affecting degradation rate is: the amount of inoculum＞the field moisture capacity＞the amount of fertilize used.【Conclusion】When the amount of inoculum was 13.46—15.48 mL•kg-1, the field moisture capacity was 56.93%—62.0% and the amount of fertilize used was 1.82—2.18 g•kg-1, the degradation rate was over 60% in air-dried soil contained clomazone 500 µg•kg-1after 30 days.

Key words: clomazone')">clomazone, degrading bacteria Y1, degradation rate