Adsorption of Nicosulfuron on Soils and Its Correlation with Soil Properties

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.