Noé Vandevoorde

Context: Chemical pesticides remain central to agricultural productivity but pose well documented risks to human health and ecosystems. While Integrated Pest Management (IPM) offers a more sustainable alternative, its adoption remains limited, partly due to the complex trade-offs that are not easily quantified and compared.,Objective: This study presents the IPM Self-Assessment Tool (ISAT), a web-based application designed to enable transparent comparison of crop protection scenarios at the field level, integrating environmental, human health, agronomic, and economic indicators.,Methods: A new harmonized pesticide risk indicator for Europe (PLEU – Pesticide Load Indicator for Europe) was developed. The PLEU covers 41 hazard metrics across three sub-indicators (Environmental Fate, Ecotoxicity, and Human Health). The PLEU was integrated into the ISAT alongside indicators for greenhouse gas (GHG) emissions and production costs, calculated using life cycle based methods. The tool was developed using data from ten European countries covering eight crops, with scenarios described by regional specialists and validated by farm advisors.,Results and conclusions: The PLEU was calculated for 502 active ingredients (441 synthetic, 61 biopesticides) across eight pesticide groups. A case study on winter wheat in Germany showed that, relative to conventional practice, an IPM scenario replacing herbicide use by mechanical weeding reduced pesticide risk by up to 75%, but at the cost of GHG emissions comparable to the conventional scenario. The ISAT enables users to identify risk-driving active ingredients and explore lower-risk alternatives, supporting informed decision-making for IPM adoption.,Significance: To our knowledge, ISAT is the first freely accessible, web-based tool integrating a harmonized pesticide risk indicator with GHG emissions and economic outcomes within a single, comprehensive field level scenario comparison. It provides a transparent decision-support platform that can help farmers, advisors, and researchers make informed decisions when designing and comparing crop protection strategies across diverse European cropping systems.

Living cover crops play a key role in reducing nitrogen leaching to groundwater during fallow periods. They also enhance soil microbial activity through root exudates, improving soil structure and increasing organic matter content. While the degradation of pesticides in soil relies primarily on microbial biodegradation, the extent to which cover crops influence this degradation remains poorly quantified. The objective of this study was to evaluate to what extent pesticide residues with contrasting physicochemical properties are affected by living cover crops. We conducted a greenhouse experiment testing two cover crop densities against a bare soil control, and quantified residues (by LC-QTOFMS) of 18 pesticide ingredients (active substances and safeners) in both soil and soil solution. We then related the observed reduction in residues to key physicochemical properties of the pesticide ingredients. Our results show that thin cover crops (0.4 t_DM ha⁻¹) reduce pesticide leaching 80 d after sowing relative to bare soil, retaining residues in the topsoil. Moreover, well-developed cover crops (1 t_DM ha⁻¹) reduce soil pesticide residues by more than 33 % for compounds with low to high water solubility (s⩽1400 mg L⁻¹) and low to moderate soil mobility (K_oc⩾160 mL g⁻¹). This effect is likely due to enhanced pesticide degradation of the retained pesticide in the rhizosphere. These findings confirm previous studies focused on individual compounds, individual cover crop types or individual soil compartments, while providing new thresholds for physicochemical properties associated with significant pesticide degradation. By directly enhancing pesticide degradation within the soil compartment where pesticides are applied, cover crops limit their transfer to other environmental compartments, particularly groundwater.

The effectiveness of pesticide reduction policies in the European Union (EU) depends critically on robust, scientifically grounded indicators that can reliably monitor pesticide-related risks across Member States. The Pesticide Load Indicator (PLI), developed in Denmark in the 2000s, offers a transparent and policy-relevant framework for assessing pesticide risk. Although it has successfully supported Denmark’s national strategies for over a decade and is drawing attention in other EU countries, several methodological limitations hinder its broader applicability. This letter identifies five such limitations and proposes corresponding updates to enhance the indicator’s scientific robustness and scalability across the EU: (1) consistent hazard assessment across compartments, (2) precautionary treatment of missing data, (3) updated hazard metric selection, (4) harmonised normalisation procedures and (5) a statistically grounded weighting protocol. These methodological updates aim to establish a harmonised PLI suitable for EU-wide policy applications, such as fiscal instruments (e.g. differentiated taxation based on hazard levels) and pesticide risk assessments.

Living cover crops play a key role in reducing nitrogen leaching to groundwater during fallow periods. They also enhance soil microbial activity through root exudates, improving soil structure and increasing organic matter content. While the degradation of pesticides in soil relies primarily on microbial biodegradation, the extent to which cover crops influence this degradation remains poorly quantified. In this paper we (1) monitored pesticide residue levels in soil and soil solution under two different cover crop densities and (2) correlated the observed reductions with physicochemical properties of the active substances. Our results show that thin cover crops (0.4 t_DM ha^-1) reduce pesticide leaching 80 days after sowing compared to bare soil, retaining the residues in the microbiologically active topsoil. In addition, well-developed cover crops (1 t_DM ha^-1) reduce soil pesticide contents by more than 33 % for compounds with low to high water solubility (s ≤ 1400 mg L^-1) and low to moderate soil mobility (K_oc ≥ 160 mL g^-1). This effect is probably due to enhanced pesticide degradation of the retained pesticide in the rhizosphere. These results confirm previous studies on individual compounds, individual cover crop types and individual soil compartments, while providing new thresholds for physicochemical properties associated with significant pesticide degradation. By directly enhancing pesticide degradation within the soil compartment where pesticides are applied, cover crops limit their transfer to other environmental compartments, particularly groundwater.

Living cover crops play a key role in reducing nitrogen leaching to groundwater during fallow periods. They also enhance soil microbial activity through root exudates, improving soil structure and increasing organic matter content. While the degradation of pesticides in soil relies primarily on microbial biodegradation, the extent to which cover crops influence this degradation remains poorly quantified. In this paper we (1) monitored pesticide residue levels in soil and soil solution under two different cover crop densities and (2) correlated the observed reductions with physicochemical properties of the active substances. Our results show that thin cover crops (0.4 t_DM ha^-1) reduce pesticide leaching 80 days after sowing compared to bare soil, retaining the residues in the microbiologically active topsoil. In addition, well-developed cover crops (1 t_DM ha^-1) reduce soil pesticide contents by more than 33 % for compounds with low to high water solubility (s ≤ 1400 mg L^-1) and low to moderate soil mobility (K_oc ≥ 160 mL g^-1). This effect is probably due to enhanced pesticide degradation of the retained pesticide in the rhizosphere. These results confirm previous studies on individual compounds, individual cover crop types and individual soil compartments, while providing new thresholds for physicochemical properties associated with significant pesticide degradation. By directly enhancing pesticide degradation within the soil compartment where pesticides are applied, cover crops limit their transfer to other environmental compartments, particularly groundwater.

Living cover crops play a key role in reducing nitrogen leaching to groundwater during fallow periods. They also enhance soil microbial activity through root exudates, improving soil structure and increasing organic matter content. While the degradation of pesticides in soil relies primarily on microbial biodegradation, the extent to which cover crops influence this degradation remains poorly quantified. In this paper we (1) monitored pesticide residue levels in soil and soil solution under two different cover crop densities and (2) correlated the observed reductions with physicochemical properties of the active substances. Our results show that thin cover crops (0.4 t_DM ha^-1) reduce pesticide leaching 80 days after sowing compared to bare soil, retaining the residues in the microbiologically active topsoil. In addition, well-developed cover crops (1 t_DM ha^-1) reduce soil pesticide contents by more than 33 % for compounds with low to high water solubility (s ≤ 1400 mg L^-1) and low to moderate soil mobility (K_oc ≥ 160 mL g^-1). This effect is probably due to enhanced pesticide degradation of the retained pesticide in the rhizosphere. These results confirm previous studies on individual compounds, individual cover crop types and individual soil compartments, while providing new thresholds for physicochemical properties associated with significant pesticide degradation. By directly enhancing pesticide degradation within the soil compartment where pesticides are applied, cover crops limit their transfer to other environmental compartments, particularly groundwater.

Living cover crops play a key role in reducing nitrogen leaching to groundwater during fallow periods. They also enhance soil microbial activity through root exudates, improving soil structure and increasing organic matter content. While the degradation of pesticides in soil relies primarily on microbial biodegradation, the extent to which cover crops influence this degradation remains poorly quantified. In this paper we (1) monitored pesticide residue levels in soil and soil solution under two different cover crop densities and (2) correlated the observed reductions with physicochemical properties of the active substances. Our results show that thin cover crops (0.4 t_DM ha^-1) reduce pesticide leaching 80 days after sowing compared to bare soil, retaining the residues in the microbiologically active topsoil. In addition, well-developed cover crops (1 t_DM ha^-1) reduce soil pesticide contents by more than 33 % for compounds with low to high water solubility (s ≤ 1400 mg L^-1) and low to moderate soil mobility (K_oc ≥ 160 mL g^-1). This effect is probably due to enhanced pesticide degradation of the retained pesticide in the rhizosphere. These results confirm previous studies on individual compounds, individual cover crop types and individual soil compartments, while providing new thresholds for physicochemical properties associated with significant pesticide degradation. By directly enhancing pesticide degradation within the soil compartment where pesticides are applied, cover crops limit their transfer to other environmental compartments, particularly groundwater.