除草剂绿草定-2-丁氧基乙酯的土壤降解特性

Degradation of triclopyr-2-butoxyethyl ester in soils

采用室内模拟试验方法,研究了绿草定-2-丁氧基乙酯在不同土壤中的降解特性.结果表明,绿草定-2-丁氧基乙酯在土壤中迅速降解,酸性土壤中其降解趋势遵循一级动力学模型,中性和碱性土壤中其降解动态不能用一级动力学模型进行简单的拟合;绿草定-2-丁氧基乙酯在土壤中的降解机制主要为化学水解作用,降解生成绿草定和丁氧基乙醇;土壤pH和土壤有机质含量是影响其土壤降解速率的主要因素,pH值越高,有机质含量越高,其土壤降解速率越快.

The degradation of triclopyr-2-butoxyethyl ester in 3 kinds of soils was studied in laboratory. The experiment results showed that triclopyr-2-butoxyethyl ester degraded quickly in soils, and its degradation behaviors could be described by first-order kinetics very well in acid soils, whereas the degradation did not fit first-order model well in neutral and alkaline soils. The principal degradation mechanism of triclopyr-2- butoxyethyl ester in soils is hydrolysis, and the degradation products are triclopyr and 2-butoxyethanol. The pH and organic matter content of soil are the main factor of degradation rate, and increased degradation of triclopyr-2-butoxyethyl ester was observed at higher pH values and higher organic matter content.