Validating GLEAMS with pesticide field data on a clermont silt loam soil

The GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) model was used to simulate the appearances of pesticides in outflow of an experimental drainage field at the South East Purdue Agricultural Center (SEPAC) in southeastern Indiana. This article presents the comparison of simulated and observed loading of AIachlor, Atrazine, Cyanazine, Carbofuran, and Chlorpyrifos in tile outflows for 1985 through 1989. The results of the simulation were close to field observations for total masses of pesticides leached from the root zone and for the overall timing of pesticide appearance in tile flows. However, the simulation of the watershed did not predict the observed arrival of pesticides in the drain during the first storm event after pesticide application. To compare the simulated results from on-site weather data and the data from nearby locations, long-term mean monthly solar radiation data for SEPAC and Indianapolis, Indiana were evaluated.