Evaluation of a simulation model for prediction of chlorsulfuron fate in an Umbrian soil

Abstract

A mathematical model described by Nicholls et al. ( Pestic. Sci., 12 (1982) 484–494) has been used to simulate the movement and the degradation of chlorsulfuron in an Umbrian soil, following application to the soil surface in autumn. Experiments were also performed on soil columns that had been surface-treated with chlorsulfuron and irrigated daily with water doses corresponding to the pluviometric records. The comparison between experimental and simulation data suggests that the model gives a reasonable description of the fate of chlorsulfuron and that it should prove of value in assessing variations in pesticide movement after different periods of application and at different sites. The differences found in the bottom layers of the columns could be due to the fact that capillary water movement is affected by the ending of the soil columns. The physical model could show a lower chlorsulfuron mobility in deeper layers where the stratum of soil ends. A defect in the physical model may have been responsible for the observed differences.