Effective Parameters in Adsorption and Leaching Potential of Butachlor by Soils in North of Iran

This study was conducted to assess sorption and leaching potential of herbicide butachlor on eight agricultural soils in Golestan province, Iran. The Kd values decreased with decreasing organic matter contents. Statistical analysis showed that organic carbon (OC), cation exchange capacity (CEC), Calcite and Clay were the effective parameters for butachlor retention. While organic matter increased pesticide sorption, the Rt ratio (ratio of calcite content to organic matter content) had an negative and counter effect. Evaluation susceptibility of butachlor to leach to groundwater showed sorption coefficient of butachlor were lowest (predicted to be most susceptible to leaching) in soils with low organic carbon and high calcite content. Thus OC content and Rt ratio as the more effective parameters governing butachlor retention and mobility in soils.