Evaluation of the GLEAMS model for pesticide leaching in Sweden

Abstract

The complexity and expensive nature of experimental procedures necessitate the use of mathematical models for evaluating the fate of agricultural chemicals as they enter into the soil and plant system. However, a transport model should be calibrated and validated for varying climatic, soils, geologic, and land use scenarios before it can be used with acceptable levels of confidence. Leaching data from lysimeter experiments conducted in Mellby soil near Uppsala, Sweden were used to calibrate and validate the Groundwater Loading Effects of Agricultural Management Systems (GLEAMS) model. Although this model is a field‐scale model for evaluating the relative impacts of agricultural management systems on surface and groundwater quality, it was put to the test for a leaching study through lysimeters. The results indicated that the GLEAMS model is capable of predicting both water and pesticide leaching through lysimeters in a reasonable manner. The study also concluded that any variability in GLEAMS predictions may be forgiven considering the variabilities that were observed in the measured data. It was also observed that GLEAMS does not perform well in partially freezing temperatures during a given computation day. This resulted in discrepancies between model simulations of drainage compared to those observed in colder periods during the experiment.