The Adsorption And Degradations Of Acetochlor In Different Types Of Soils

As a kind of glebe herbicide, acetochlor is widely used all over the world. Whereas, it is also defined as environment pollute and the potential ecological safety problems would arise after large amount application for a long time. The time-affection of acetochlor is highly related to different ecology process,such as adsoption-desorption, eluviation, volatilization, biodegradation and assimilation or metabolism processes with the adsorption and biodegradation were the key factors. Therefore, the investigation and definitude of the adsorption and biodegradation of acetochlor as well as the influence factors was essential for the acetochlor application reasonably, furthermore to decrease the environment risk. For this aim, our research first focused on the different adsorption dynamics of acetochlor as well as how soil organic matters and mineral composition effected on the adsorption characteristics. In the second, the microbial actions were concerned in the degradation process of acetochlor, and finally, the dynamics of dehydrogenase was traced to indicate the potential risk of dehydrogenation in different concentrations.The main results of our investigation include as: 1) the research on the adsorption characteristics of acetochlor showed that acetochlor was easily absorbed by different soils and the absorption dynamics was fitted well to the linear Freundlich equation. The absorption of acetochlor was observed to be effected significantly by the content of soil organic matters and mineral composition; 2) compared to un-sterilized soil, the residue of acetochlor in sterilized soil samples increased greatly and meanwhile the residue magnitude was highly relative with soil microbial biomass carbon, indicating that the microbial activity was the key factor to control the acetochlor degradation; 3) the activity of dehydrogenase in different types of soil was all restrained after acetochlor application, suggesting what. Therefore, although the toxicity of acetochlor is relatively low, it can still influence the stability of soil biological and chemistry environment. So, the acetochlor must be applied in different levels based on the soil physical and biochemical properties to improve the weed-remove efficiency as well as decrease the environment risk.