 Dicamba is likely to be more rapidly degraded in soils with high microbial populations, but dissipates more slowly in hardwood forests and wetlands than would be expected from the results of laboratory studies.At a level of 10 mg/kg in sandy loam soil, dicamba caused a transient decrease in nitrification after two but not three weeks of incubation.The investigator determined that the decrease in nitrification is not substantial and does not suggest the potential for a prolonged impact on microbial activity.