Effect of charcoal amendment on adsorption, leaching and degradation of isoproturon in soils

Abstract The effects of charcoal amendment on adsorption, leaching and degradation of the herbicide isoproturon in soils were studied under laboratory conditions. The adsorption data all fitted well with the Freundlich empirical equation. It was found that the adsorption of isoproturon in soils increased with the rate of charcoal amended (correlation coefficient r  = 0.957 ⁎⁎ , P DT 50 ) in soils greatly extended when the rate of added charcoal inceased from 0 to 50 g kg − 1 (for Paddy soil, DT 50 values increased from 54.6 to 71.4 days; for Alfisol, DT 50 from 16.0 to 136 days; and for Vertisol, DT 50 from 15.2 to 107 days). The degradation rate of isoproturon in soils was significantly negatively correlated with the amount of added charcoal. This research suggests that charcoal amendment may be an effective management practice for reducing pesticide leaching and enhancing its persistence in soils.