Indian Agricultural Research Institute, New Delhi, India.
Department of Agriculture, Government of West Bengal, India.
Environ Toxicol Pharmacol. 2012 Sep;34(2):307-314. doi: 10.1016/j.etap.2012.04.014. Epub 2012 May 15.
The research was carried out to ascertain the effect of three chloroacetanilide herbicides, alachlor, butachlor and pretilachlor on soil microbial biomass growth and activity. Laboratory experiments were performed in a silty clay loam soil to relate changes of soil enzymatic activity to the herbicide persistence under laboratory condition up to 42 days at three application rates. The results showed that all the three herbicides caused enhancement of dehydrogenase activity. Higher concentrations of herbicide resulted in enhancement of the enzymatic activity. In addition, a similar trend was observed in β-glucosidase and acid phosphatase activity, although urease activity decreased upon incubation for 42 days as compared with initial soil incubation values. Based on the extent of impact for dehydrogenase activity in soil, the order was pretilachlor>alachlor>butachlor; whereas in case of urease activity, the order changed to pretilachlor>butachlor>alachlor. The soil half-lives of alachlor, butachlor and pretilachlor respectively, were 9.3, 12.7 and 7.3 days, which could be accounted for in terms of their respective chemical structures, as well as variable adsorption, degradation, differential effects of the agents on soil microbes. Soil management practices and the differing physicochemical properties of the herbicides may contribute to their rates of decay in soil.
本研究旨在确定三种氯乙酰胺类除草剂（甲草胺、丁草胺和丙草胺）对土壤微生物生物量生长和活性的影响。在粉质粘壤土中进行了实验室实验，以在三个施用量下，在实验室条件下将土壤酶活性的变化与除草剂的持久性相关联，直至 42 天。结果表明，所有三种除草剂均能增强脱氢酶活性。较高浓度的除草剂会增强酶活性。此外，β-葡萄糖苷酶和酸性磷酸酶活性也呈现出类似的趋势，尽管与初始土壤孵育值相比，在孵育 42 天后，脲酶活性下降。基于土壤中脱氢酶活性的影响程度，其顺序为丙草胺>甲草胺>丁草胺；而对于脲酶活性，其顺序变为丙草胺>丁草胺>甲草胺。甲草胺、丁草胺和丙草胺在土壤中的半衰期分别为 9.3、12.7 和 7.3 天，这可以从它们各自的化学结构以及不同的吸附、降解、对土壤微生物的不同作用来解释。土壤管理措施和除草剂的不同物理化学性质可能会影响它们在土壤中的降解速度。
