Conference Agenda

This study estimates the risks of agricultural pesticides on non-target organisms and the environment by combining detailed pesticide application data for 2015 with the Danish risk indicator Pesticide Load. We quantify and map the pesticide load of 59 pesticides on 28 crops and pastures in the EU. Furthermore, we investigate how recent bans on 14 pesticides in the EU could reduce pesticide use and load. Key findings show that the highest pesticide loads per hectare occur in Cyprus and the Netherlands due to high application rates and a high proportion of vegetable production. Chlorpyrifos caused the highest pesticide load per hectare on more

than half of the assessed crops before its ban. The ban of 14 pesticides between 2018 and 2023 potentially reduced pesticide loads by 94%, but unobserved substitution effects could offset pesticide load reductions. Although bans on active substances are justified to control certain endpoint risks, our results highlight the potential weaknesses of bans that merely shift risks. These findings contribute to the ongoing scientific and societal discourse on efficiently mitigating pesticides’ impacts on non-target organisms and the environment. However, to improve the evaluation of pesticide use, it is vital to enhance the reporting on detailed pesticide use for individual crop-pesticide combinations.

Bio-based fertilizer production can provide a technological solution to recover nutrients from organic waste streams while simultaneously offering an alternative to mineral fertilizers. Market-based research plays a vital role in the development and adoption of novel fertilizer solutions. While several researchers have investigated sustainable business models for circular solutions in agriculture, the question remains whether the introduction of these business models will facilitate the adoption of bio-based fertilizers amongst conventional farmers. To answer this question, this study takes on an agent-based approach coupled with a linear-programming framework to account for rational and behavioral factors. Given the decision-making process of the farmers and the specifications of the scenarios, which indicate different business models, multiple experiments are conducted to investigate the effect of parameters such as cooperativeness and increase in energy prices on the adoption of bio-based fertilizers. The results not only provide insights into the distribution of decision strategies but also shed light on the final fertilizer mixes resulting from these decisions. The study strengthens the idea that bio-based fertilizers can play a role in conventional Flemish horticulture. The integration of behavioral and rational aspects provides a systematic overview of fertilizer-related decision-making by farmers. The findings will be of interest to policymakers, informing them about the relevant parameters to consider in the design of policies targeting nutrient circularity or aiming to find alternatives to mineral fertilizers and manure.

Organic and conventional farmers face the same pests but have heterogeneous tools and incentives to control them. This paper aims to theoretically and empirically characterise the strategic interactions to control pests that occur between these two types of farmers. Specifically, we develop a game theory model with two heterogeneous agents facing the same public bad to derive theoretically-consistent propositions related to the impacts of their specific characteristics on their respective pest control efforts. Our analyses indicate that organic farmers are likely to free-ride on the contributions of the conventional farmers when they manage a smaller part of the landscape, and vice versa. These strategic interactions

are theoretically exacerbated when the exposure to pest abundance decreases, or when the heterogeneity of treatment efficacy or treatment expected payoffs between the two agents increase. Using exhaustive French data on insecticide purchases against the vector of a particular vine disease (Flavescence dorée), we provide empirical supports for all these propositions. Our preferred estimates indicate that organic farmers free-ride on conventional farmers' efforts until they represent about 6% of the landscape. Beyond this threshold, conventional farmers' efforts decrease and are partially substituted by those of organic farmers (by a factor 0.8 for 1). Conventional farmers eventually start to free-ride when organic farmers manage 72% of the landscape. These results are robust to several sensitivity analyses. We empirically show that farmers' free riding behaviors are particularly triggered by low exposures to pest abundance, but almost disappear for high pest abundance. We additionally show that the heterogeneity of treatment efficacy and expected payoffs between farmers do affect their strategic interactions, thought to a limited extent.

Dissimilar to the increase in organic good consumption, the transition from conventional farming to organic was slowdown recently despite transparent benefits of organic farming to farmers. To solve this dilemma, understanding the roles of farmer preferences and their social incentive factors on their willingness to convert to organic farming is necessary. We conducted a lab-in-the-field experiment to elicit farmer's risk, ambiguity, time and social preferences along with a survey to obtain their social and other control factors and retrieved 311 completed respondents in Vietnam. Our study employ an endogenous fractional model to reveal the impact of farmer preferences and their social incentive factors on their willingness to convert to organic farming. Specifically, the results indicate farmer's risk preference is a good instrument to measure the endogenous effect of farmer's ambiguity preference on their intended land conversion. Farmers who are future bias and has low discount rate willing to adopt organic farming. Regarding social factors, social trust and learning stimulate the land conversion percentage of farmers to organic farming. Meanwhile, social network significantly demotivates their land transformation. To promote land conversion to organic farming, policymakers should design adjustable support schemes to decrease farmer's risk/ambiguity aversion such as Common Agricultural Policy (CAP) enacted in the EU. Timely support for early organic adopters is also substantial because organic farming is a long-term investment business.