Degradation and the Influencing Factors of Acetochlor in Soils

The degradation of acetochlor in soils from different climatic zon e of China was studied in laboratory. The results showed that half-life of ace tochlor was 2.8～5.1 d in non-sterilized soil and 20.0～25.1 d in sterilized soil, when the soil was treated with acetochlor of 1.25 mg·kg-1, 2.5 mg·k g-1 and 5.0 mg·kg-1, respectively. Acetochlor depletion was faster in alka line soil such as cinnamon soil from North China, with half-life time of 4.2 d ,than that in acid soil such as terra nera soil from Northeast China and terra r ossa soil from South China, with half-life time of 6.5～10.7d. Degradation ra te of acetochlor increased with the increase of soil water content and environme ntal temperature. Light intensity also had some influence on the degradation of acetochlor. Microorganism was a critical factor among all the experimental facto rs that variedly influenced acetochlor depletion in soils, and could accelerate greatly the degradation in soil The environmental factors favorable for the grow th of microbes could also enhance the degradation of acetochlor.