integrate pesticide behaviour, taking into account farmers’ phytosanitary practices.
Pesticide contamination at the catchment scale was first investigated in two small
agricultural areas: the Orgeval and the Vesle. This paper is a synthesis of the work
done in the PIREN-Seine research programme concerning the modelling of pesticide
transfer. We present here how pesticide uses were collected, the modelling approach
and the results for atrazine and its by-product DEA on two basins: the Orgeval and
the Vesle. These studies highlight the difficulty of the spatio-temporal approach to
modelling the fate of pesticides in the Seine basin.
2 Study Sites
The pesticide fate model was designed to gather input databases such as soil
characteristics, climatic data, pesticide properties and phytosanitary practices.
Given that the database is not available for the latter, an estimation of annual
quantities of each AI, the application schedule and spatial distribution of application
on the catchment must be at least documented. The effort needed for inquiries on
pesticide applications is directly related to the size of the watershed. Therefore, the
Orgeval site was considered for a long-term study, while the Vesle site was chosen
for a spatial approach.
2.1 Presentation of the Orgeval and Vesle Basins
The Orgeval watershed (104 km
2 ) is located 70 km east of Paris (Fig. 1) where
hydrological and biogeochemical cycles have been studied since 1962. It is situated
on the Brie plateau, which is one of the most productive agricultural areas in France,
between 140 and 180 m above sea level. The deep and low permeability clay loams
result from the decomposition of limestones and millstones of the underlying Brie.
Drainage has allowed intensive agricultural development of these silts of the Brie
plateau. Consequently, this basin is dominated by agricultural areas (81%) and
forests (18%). Roads and urban areas account for only 1% of the land area. Cereals
are the main crops. Soft wheat accounts for more than 40% of crops and maize for
about 14% for the 1988–2007 period. Some specific crops such as broad bean and
flax are also cultivated in the Orgeval basin (5% and 4%, respectively), whereas
sugar beet, barley and rapeseed are less widespread, compared to data for the Seineet-Marne department.
The Vesle watershed (1,460 km
2 ) is located in one of the major agricultural
regions of the Seine basin: the Champagne area (Fig. 1). Seventy-six percent of the
basin is covered by agricultural lands, while the remaining surface is divided into
forest (17%) and urban areas (7%). The city of Reims is situated in the downstream
part of the basin. The basin is mainly covered by field crop systems: wheat (30%),
barley (18%), sugar beet (13%) and alfalfa (12%). On this catchment, maize is
mainly inserted into 5-year-long rotations such as beetroot (or pea or rapeseed) –
wheat – maize – wheat – barley. Champagne grapes are a specific crop located on the
How Should Agricultural Practices Be Integrated to Understand and. . .
143
Pesticide contamination at the catchment scale was first investigated in two small
agricultural areas: the Orgeval and the Vesle. This paper is a synthesis of the work
done in the PIREN-Seine research programme concerning the modelling of pesticide
transfer. We present here how pesticide uses were collected, the modelling approach
and the results for atrazine and its by-product DEA on two basins: the Orgeval and
the Vesle. These studies highlight the difficulty of the spatio-temporal approach to
modelling the fate of pesticides in the Seine basin.
2 Study Sites
The pesticide fate model was designed to gather input databases such as soil
characteristics, climatic data, pesticide properties and phytosanitary practices.
Given that the database is not available for the latter, an estimation of annual
quantities of each AI, the application schedule and spatial distribution of application
on the catchment must be at least documented. The effort needed for inquiries on
pesticide applications is directly related to the size of the watershed. Therefore, the
Orgeval site was considered for a long-term study, while the Vesle site was chosen
for a spatial approach.
2.1 Presentation of the Orgeval and Vesle Basins
The Orgeval watershed (104 km
2 ) is located 70 km east of Paris (Fig. 1) where
hydrological and biogeochemical cycles have been studied since 1962. It is situated
on the Brie plateau, which is one of the most productive agricultural areas in France,
between 140 and 180 m above sea level. The deep and low permeability clay loams
result from the decomposition of limestones and millstones of the underlying Brie.
Drainage has allowed intensive agricultural development of these silts of the Brie
plateau. Consequently, this basin is dominated by agricultural areas (81%) and
forests (18%). Roads and urban areas account for only 1% of the land area. Cereals
are the main crops. Soft wheat accounts for more than 40% of crops and maize for
about 14% for the 1988–2007 period. Some specific crops such as broad bean and
flax are also cultivated in the Orgeval basin (5% and 4%, respectively), whereas
sugar beet, barley and rapeseed are less widespread, compared to data for the Seineet-Marne department.
The Vesle watershed (1,460 km
2 ) is located in one of the major agricultural
regions of the Seine basin: the Champagne area (Fig. 1). Seventy-six percent of the
basin is covered by agricultural lands, while the remaining surface is divided into
forest (17%) and urban areas (7%). The city of Reims is situated in the downstream
part of the basin. The basin is mainly covered by field crop systems: wheat (30%),
barley (18%), sugar beet (13%) and alfalfa (12%). On this catchment, maize is
mainly inserted into 5-year-long rotations such as beetroot (or pea or rapeseed) –
wheat – maize – wheat – barley. Champagne grapes are a specific crop located on the
How Should Agricultural Practices Be Integrated to Understand and. . .
143