Risk mitigation measures for pesticide runoff: How effective are they?

Abstract

BACKGROUNDOne of the most important sources of pesticide pollution of surface waters is runoff and erosion from agricultural fields after rainfall. This study analyses the efficacy of different risk mitigation measures to reduce pesticide runoff and erosion inputs into surface waters from arable land excluding rice fields.RESULTSThree groups of risk mitigation measures were quantitatively analyzed: vegetative filter strips, micro‐dams in row crops and soil conservation measures. Their effectiveness was evaluated based on a meta‐analysis of available experimental data using statistical methods such as classification and regression trees, and exploratory data analysis. Results confirmed the effectiveness of vegetative filter strips and micro‐dams. Contrary to common assumption, the width of vegetative filter strips alone is not sufficient to predict their effectiveness. The effectiveness of soil conservation measures (especially mulch‐tillage) varied widely. This was in part due to the heterogeneity of the available experimental data, probably resulting from the inconsistent implementation and the inadequate definitions of these measures.CONCLUSIONBoth vegetative filter strips and micro‐dams are effective and suitable, and can therefore be recommended for quantitative assessment of environmental pesticide exposure in surface waters. However, the processes of infiltration and sedimentation in vegetative filter strips should be simulated with a mechanistic model like Vegetative Filter Strip Modeling System, VFSMOD. The reduction effect of micro‐dams can be modelled by reducing the runoff curve number, e.g., in the pesticide root zone model, PRZM. Soil conservation measures are in principle promising, but further well‐documented data are needed to determine under which conditions they are effective. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Linking chemical surface water monitoring and pesticide regulation in selected European countries

“…The depth of soil disturbance and the type of machinery is specified (BLW 2021 ). In DE, there is no specification other than the field may not be tilled with a mouldboard plow (Klein et al 2023 ).…”

“…The monitoring revealed exceedances of RACs in 80% of monitoring sites and 60% of event-driven samples (Liess et al 2021 ). Primary reasons for this non-compliance with regulatory goals related to PPP authorization (concentrations in the field below RAC) were identified to lie within (i) the inertia of the risk assessment where re-evaluation of a.s. and subsequently PPP is generally intended only every 10–15 years, but PPP may remain authorized for years even if the current state of knowledge suggests unacceptable environmental risks for the authorized use; (ii) an overestimated efficacy of risk management measures (Klein et al 2023 ; Vormeier et al 2023 ); (iii) the limitation of the environmental risk assessment to review the use of a single PPP during authorization and thereby neglecting other uses of the same PPP in the same catchment and pesticides mixtures typically occurring in reality.…”