Biochar mediated alterations in herbicide breakdown and leaching in soil

► Biochar sequesters carbon in soil and significantly affects pesticide behavior. ► Biochar prevents pesticide leaching but enhances pesticide persistence in soil. ► Pesticides preferentially associate with biochar causing concentrated hotspots in soil. ► The effect of biochar on pesticide behavior lasts for long periods in soil (>2 years). ► Biochar may potentially suppress the effectiveness of pre-emergent herbicides in soil.