[Effects of solution pH and simulated acid rain on the behavior of two sulfonylurea herbicides in soil].
By the methods of batch equilibration and leaching, this paper studied the effects of solution pH and simulated acid rain on the behavior of bensulfuron-methyl and metsulfuron-methyl in soil. The results showed that the adsorption isotherms of these two herbicides fitted Freundlich equation well, and their adsorbed amounts reduced obviously with the increasing pH of water-soil system, which in turn promoted the translocation of the herbicides in soil. The adsorption coefficient (Kf) was positively correlated with soil organic matter and clay contents, while negatively correlated with soil pH. The higher pH of simulated acid rain had a greater contribution on the leaching of the two sulfonylurea herbicides, and their leached amount was increased with increasing acid rain. There was a close relationship between the leaching of the herbicides and the properties of soil. The soils with higher contents of organic matter and clay had a greater retention capability to the herbicides.
Zhang
Wei
W
College of Plant Protection, Southwest University, Chongqing 400716, China. zw5116@yahoo.com.cn
Wang
Jin-Jun
JJ
D015258:Acid Rain; D001190:Arylsulfonates / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012987:Soil / Q000032:analysis*; D013453:Sulfonylurea Compounds / Q000737:chemistry*
D015258:Acid Rain; D001190:Arylsulfonates; D006540:Herbicides; D012987:Soil; D013453:Sulfonylurea Compounds; C050296:metsulfuron methyl; C071475:methyl bensulfuron