Ditch parameterisation for the aquatic exposure assessment of plant protection products in the Netherlands by sideways and upward spraying in fruit orchards

Abstract

Pests and diseases in fruit-orchards and lane tree-nurseries are frequently treated with pesticides, that are applied by sideways or upward spraying. To assess the risk to aquatic organisms associated with the application of these pesticides, specific scenarios are required as part of a tiered assessment scheme. In these scenarios, next to spray drift, drainage is included as well as entry route of pesticide in the ditch. This report describes the hydrological parameterisation of the edge-of-field ditch model next to fruit-orchards. This parameterised model is part of the Dutch exposure assessment scenarios for fruit-orchards. This report is an update of WEnR report 2850. In addition to the hydrological parameterisation described in WEnR report 2850, the drainage entry route to the ditch is now part of the hydrological parameterisation described.

Scenarios for exposure of aquatic organisms to plant protection products in the Netherlands : Part 2: Sideways and upward spraying in Dutch fruit crops (final report)

“…We refer to Ter Horst et al ( 2020) for further detail. Also the parameterisation of the soil-hydrological model (SWAP) underlying the PEARL model is described in Ter Horst et al (2020). The parameterisation of the evaluation ditch is discussed in Chapter 5.…”

“…Each of these strips contribute to drainpipes that discharge to the edge-of-field ditch. Given that the soil-hydrological model (SWAP model) is a one-dimensional model, Ter Horst et al (2020) concluded that the most realistic approach would be to simulate drainage discharge fluxes for the tree strip and the grass strip as separate systems and to merge the water and pesticide mass fluxes in a follow up step based on area weighting 10 (on a 1-h basis). Below the parameterisation of the pesticide fate model (PEARL) is discussed, that uses the hydrological output from the hydrological model.…”

“…Below the parameterisation of the pesticide fate model (PEARL) is discussed, that uses the hydrological output from the hydrological model. For further detail on the hydrological parameterisation we refer to Ter Horst et al (2020).…”

“…drip irrigation for the trees and the supply of water by sprinkler irrigation in case of night frost during the blooming period. We refer to Ter Horst et al (2020) for further detail of the parameterisation.…”

“…Details on different aspects of the methodology can be found in Holterman et al (2017Holterman et al ( , 2018Holterman et al ( , 2021, Wipfler et al (2018), Ter Horst et al (2020, Van de Zande and Ter Horst (2019), and . Furthermore, this report contains results of a number of example simulations.…”