烟嘧磺隆在土壤中的吸附及与土壤性质的相关性研究

Adsorption of Nicosulfuron on Soils and Its Correlation with Soil Properties

采用平衡振荡法研究了烟嘧磺隆在8种不同类型土壤中的吸附,结果表明,其吸附过程均符合经典的Freundlich模型,最大吸附常数为6.891,最小吸附常数为0.798。根据土壤有机吸附常数和吸附自由能的大小对该除草剂的移动性能进行了评价,认为其在8种土壤中均以物理吸附为主,且具有中等或较高的移动性能。通过对吸附常数Kf与土壤有机质含量、粘土含量和pH值的关系进行分析,发现土壤有机质含量、粘土含量和pH值在吸附过程中均属支配因素,Kf与土壤有机质含量、粘土含量呈正相关,而与土壤pH值呈负相关。

The adsorption of nicosulfuron, a new sulfonylurea herbicide in eight different types of soils was investigated using the batch equilibration technique. The results showed that the adsorption isotherms of nicosulfuron in soils fitted the Freundlich equation well, and the adsorption values of nicosulfuron,calculated by Freundlich equation, ranged from 0. 798 to 6. 891. Further calculation and analysis about Koc, the mean partial free energy and the free energy of adsorption of nicosulfuron on soil performed middle or higher translocation in soils. Furthermore, it was found that the Kf values increased with increasing of organic matter （OM） and clay content, while, decreased with increasing of the soils pH values due to the nicosulfuron characters and solution in water depending on pH. The simple linear correlations were regressed between OM, clay contents or soils pH values and the values of adsorption coefficient （Kf） ,indicated that OM, clay contents and the soils pH were the dominating factors influencing the nicosulfuron retention in all of the systems.