Landscape features support natural pest control and farm income when pesticide application is reduced

Global and EU targets aim to reduce pesticide use by at least 50% by 2030 to mitigate negative environmental impacts from intensive agricultural systems. Intensive agriculture has led to simplified landscapes and biodiversity loss, reducing the effectiveness of natural pest control (NPC) provided by natural enemies like predatory insects and birds. These natural enemies can reduce reliance on synthetic pesticides. Current research lacks general quantification of NPC as an ecosystem service and its link to crop yields, hindered by data limitations, inconsistent results, ecological complexity, and context-specific findings. Similarly, economic valuation of NPC is often limited to specific crops or locations. This study addresses these gaps by comprehensively assessing the contribution of LF-NPC potential in the EU, quantifying its impact on crop yields and economic value under reduced pesticide use.

Existing literature establishes the link between landscape complexity and enhanced natural pest control. Studies show that diverse landscapes support higher abundance of natural enemies by providing shelter and alternative prey. However, a general quantification of the ecosystem service of NPC and its economic value remains lacking. While some studies estimate the monetary value of NPC, they often focus on specific contexts, hindering broader application. This study aims to fill this gap by providing a comprehensive, Europe-wide assessment.

This study uses a three-part methodology. First, it estimates regional crop yield gaps between conventional and organic farming attributable to pesticide use differences. This utilizes data from the EU Farm Accountancy Data Network (FADN) for ten arable crops, controlling for factors like fertilizers and soil improvers using a linear multiple regression model (equation 1). The yield gap is calculated as a percentage (equation 2). Second, it assesses the contribution of LF-NPC potential to these yield gaps. A spatially explicit LF-NPC map at 100-meter resolution, derived by combining geospatial data on landscape elements with field surveys of flying insect predators, is used. This is combined with agricultural intensity and crop mask data to refine crop-specific LF-NPC scores at the regional level. The relationship between LF-NPC potential and yield gaps is analyzed using a mixed-effect model (equation 3), accounting for crop-specific variations. Third, a partial equilibrium model (CAPRI) simulates the EU agricultural sector in 2030 under a reduced pesticide use scenario, incorporating the estimated yield gaps as exogenous shocks. An 80% reduction in pesticide costs is also implemented. The model recalibrates to determine new equilibrium.

The analysis included ten arable crops. Yield gaps attributable to pesticide use between organic and conventional farming averaged -15%, with crop-specific variations ranging from -8% (legumes) to -23% (rye). Regional differences were also substantial. A positive correlation was observed between LF-NPC potential and yield gaps for nine out of ten crops. The strength of correlation varied, ranging from 0.14 (corn) to 0.4 (potatoes). For crops with many observations, the relationship was statistically significant. The mixed-effect model showed that a one-unit increase in LF-NPC potential resulted in a 4.4 percentage point reduction in the yield gap. The CAPRI model simulation indicated that a one-unit increase in LF-NPC potential, on average, resulted in a 4.4 percentage point increase in productivity and a similar increase in farm income. However, the economic impact varied regionally depending on crop mix and cost structure.

The findings highlight the economic benefits of incorporating landscape complexity to enhance LF-NPC and support agricultural productivity under reduced pesticide scenarios. The positive impact of LF-NPC on yield gaps suggests a beneficial feedback loop where natural enemies mitigate productivity losses from reduced pesticide use. The study uses a causal inference approach using observational data, making assumptions to connect LF-NPC to agricultural productivity. The focus is on direct benefits; other positive externalities of LF-NPC (e.g., soil erosion control) are not included. Similarly, the study doesn't assess the full range of benefits from reduced pesticide use or the costs of landscape redesign. The use of flying invertebrates as a proxy for LF-NPC is a limitation, as it doesn't encompass all natural enemies. Despite these limitations, the results fill a gap in quantifying the benefits of LF-NPC across Europe, providing a valuable reference point for investment decisions.

This study provides the first Europe-wide quantification of the benefits of landscape features supporting natural pest control (LF-NPC) in reducing yield gaps and increasing farm income under reduced pesticide use scenarios. The findings highlight the potential of integrating LF-NPC into agricultural policies and practices to achieve sustainability goals without compromising productivity. Future research should focus on refining the LF-NPC index to include a wider range of natural enemies and on quantifying the costs and benefits associated with landscape redesign. Integrating dynamic models that account for the complex interplay between pesticides, biodiversity, and NPC would also improve the accuracy of predictions.

The study's reliance on observational data and the use of flying invertebrates as a proxy for LF-NPC are key limitations. The economic model doesn't fully account for all externalities of reduced pesticide use or landscape redesign costs. The absence of precise farm geolocation in FADN data necessitates a regional-level analysis, potentially masking local-level variations in the effectiveness of LF-NPC. The assumptions made in the model, such as the correlation between seed costs and pest resistance, may also influence the results.