This short summary from the National Pesticide Information Center reviews the effects of biochar on pesticides in soil. Biochar can bind to pesticides in soil. The effect of biochar on pesticide residues in soil varies. Some pesticides may bind to biochar more strongly than others. The binding potential depends on many things. Biochar may be useful because it could potentially hold onto a pesticide and make it less likely to move down through soil toward shallow groundwater.