Field study on mobility and persistence of linuron and monolinuron in agricultural soil

A field site equipped with suction cup lysimeters was installed at Trevigli o (BG) to assess the migration capacity of the herbicides linuron and monol inuron from topsoil to groundwater and to verify the appearance of their re levant transformation products in soil and water samples. A constant hydrau lic head was applied in order to develop water saturation conditions in the upper layers. KCI was used as a tracer to evaluate water infiltration velo city through the vertical son profile. The constant hydraulic head accelera ted infiltration rates, while herbicide concentrations reached maximum cont amination because soil adsorption capacity was underdeveloped. The results indicated two main processes of pesticide transport: firstly transport due mainly to water infiltration through macropores; secondly the transport dri ven by matrix flow. Linuron was found to be the most mobile herbicide, whil e chloroanilines were found to be the major transformation products of the herbicides considered.