Page 117 - Modelisation du devenir des pesticides...
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Points clés
Points clés
BACKGROUND :
A pesticide fate module was implemented in the crop model STICS in or-
der to enhance the components of the diffuse agricultural pollution already
simulated by the model. The pesticide fate process developed in the model
is based on formalisms currently used in the literature. The objectives of the
study were i) to evaluate the model performances using experimental data
from three sites, one in the Netherlands and two in northern France and ii) to
compare the simulations to predictions based on the same datasets and made
with several pesticide fate models. The evaluation was carried out with three
different herbicides : bentazone, isoproturon and atrazine. As the design of the
field measurements varied, the model assessment was performed either on che-
micals concentration profiles or on pesticide losses at the bottom of lysimeters.
The strategy applied in this study used observed or recommended values for
the pesticide properties instead of performing a model calibration.
RESULTS :
The improved version of the STICS model was able to reproduce the observed
order of magnitude of the pesticide content or flux, even though the pesticides
used had contrasting properties. The range of results compared well with the
other pesticide fate models.
CONCLUSION :
The STICS model is now able to simulate nitrogen and pesticide fluxes,
with reasonable accuracy at three different experimental sites and can be ap-
plied to experimental basins to estimate the relative leaching potential due to
agricultural practices.
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