Agron. Sustain. Dev. 25 (2005) 35-44
DOI: 10.1051/agro:2004053

Application of the RICEWQ-VADOFT model to simulate leaching of propanil in rice paddies in Greece

Dimitrios G. Karpouzas^a, Ettore Capri^a and Euphemia Papadopoulou-Mourkidou<sup>b

a</sup>  Istituto di Chimica Agraria ed Ambientale, Universita Cattolica del Sacro Cuore, 29100 Piacenza, Italy
^b  Aristotle University of Thessaloniki, Laboratory of Pesticide Science, School of Agriculture, Thessaloniki 54124, Greece

(Received 29 June 2004; accepted 11 August 2004)

Abstract - In recent years models have become an integral part of the pesticide registration processes. However, there are still no validated models which can adequately describe the specific conditions of rice paddies. Accordingly, this study aimed to evaluate the capability of a proposed model, the RICEWQ-VADOFT model, to simulate leaching of propanil. Model performance was evaluated with a data set derived from a field study (1993-1994) carried out in five paddy fields in the southern part of the Axios river basin. Predicted and measured concentrations of propanil leaching to the deeper soil layer were in good agreement. The Root Mean Square Error (RMSE) and Modeling Efficiency (EF) values calculated for three of the five studied fields varied between 39.4-46.1 and 0.813-0.867, respectively, indicating good model performance. However, little agreement between predicted and observed pesticide concentrations was evident in the remaining two paddies. This was attributed to the presence of preferencial flow mechanisms in these particular fields, which facilitated the rapid transport of high concentrations of propanil into the deeper soil layers, and which the model was not able to predict.

Key words: RICEWQ-VADOFT / PECs / herbicides / leaching / rice paddies

Corresponding author: Dimitrios G. Karpouzas dimitrios.karpouzas@unicatt.it

© INRA, EDP Sciences 2005