Comparison of PELMO and PEARL FOCUS models for assessing herbicide leaching in the three selected soil types in the Apače valley area

Abstract

FOCUS PELMO 3.3.2 and PEARL 3.3.3 are well established models for predicting pesticide leaching and can be used also for the pesticide registration purposes in the EU Member States. Results of both models were compared, namely the predicted leached concentrations of selected herbicides (Lumax Primextra Gold 720 SC and Primextra 500 liquid) for the standard FOCUS scenarios, as well as for the specific environmental scenarios that are typical for Apače Valley. Long term daily data from meteorological station Murska Sobota and soil data of three selected soil profiles (Fluvisol, Gleysol, and Stagnosol) were used. The results demonstrate that predicted leached concentrations of selected herbicides under standard FOCUS scenarios are in PEARL generally higher than in PELMO model, however under specific (realistic) scenarios in Apače Valley for the period 1984-2009, this finding is confirmed only in selected (the most vulnerable) shallow Fluvisol soil, while the predicted leached concentrations in the other two soil profiles are slightly higher when using PELMO model.