Degradation of Carbendazim in Paddy Soil and the Influencing Factors
多菌灵在农田土壤中的降解及其影响因子研究

The influences of microorganism, soil moisture and cadmium (Cd) on degradation of carbendazim in paddy soil were investigated with laboratory microcosm experiments. The results showed that the half-life of carbendazim (5.0 mg·kg-1and 10.0 mg·kg-1) in sterilized soils was 12.6-13.8 times of those in non-sterilized soils. The half-life of carbendazim was decreased by 32.1%-37.1% when the soils were inoculated with carbendazim-degrading strains. When the soil moisture was increased from 40% to 60% or 80% of water holding capacity, the half life of carbendazim was decreased by 46.2% or 74.0%, respectively. Low level of Cd (5 mg·kg-1) enhanced the degradation of carbendazim in soils with half-life time decreased by 32.1%-52.4%, but high level of Cd (50 mg·kg-1) inhibited the degradation of carbendazim in soils with half-life time increased by 92.6%-103.0%. For the soils inoculated with carbendazim-degrading strains, the half life of carbendazim was decreased by 34.0%-34.4% with the addition of low level of Cd (5.0 mg·kg-1), while the half life time was increased by 74.4%-109.4% with the addition of high level of Cd (50 mg·kg-1). The results demonstrate that indigenous microorganisms is a critical factor that influences carbendazim degradation in soils, and that carbendazim-degrading strains, high soil moisture and low Cd level enhance the degradation of carbendazim.