Degradation of methyl parathion in soil and Chinese chive by strain DLL-1
菌株DLL-1降解土壤和韭菜中甲基对硫磷的研究

Degradation of methyl parathion in soil and Chinese chive by strain DLL-1 was studied. Usage of methyl parathion at 7.5, 15, and 22.5 kg(a.i.).hm-2 resulted in the average amount of residue of 0.663, 1.270, and 1.901 mg.kg-1 in Chinese chive respectively. The natural degradation rate was 98.94%, 96.44%, and 96.04% corresponding to the 3 levels of usage. The amount of pesticide residue could be significantly decreased through the application of high effective degrading microbial agents. The amount of pesticide residue in Chinese chive and soil was 0.269 and 0.099 mg.kg-1 with the usage of 75 kg.hm-2 of degradation bacterium, which was decreased by 78.82% and 98.68% compared with the control. Increasing the bacterium usage led to the increase of degradation rate. Usage of degradation bacterium more than 75 kg.hm-2 did not increase the degradation rate further. The best time of the application of the degrading microbe was 3 days after the application of the pesticide.