Pesticide soil transport models: Model comparisons and field evaluation

Using an experimental data set obtained in a field trial in Italy, three models forecasting pesticide behaviour in root/vadose zone of the soil were tested. PRZM, BAM and LEACHM were used simulating metolachlor and atrazine at different depth of the soil. Input model parameters for the chemodynamic herbicide properties, were obtained from literature data base while weather and soil data were derived from the experimental field. In all cases the results from the models agreed with the observed data in particular for the top soil. In the 30–50 cm ‐ soil depth, the measured and predicted concentrations were much variable and they agreed only in few cases within a magnitude factor of 5–10. The differences between the models were measured mainly in soil hydrological balance.

Key Words:

• Pesticide model
• leaching
• persistence
• herbicide
• atrazine
• metolachlor