Engaging citizens in open data hackathons provides opportunities for innovation and the generation of new services and products. This paper aims to explore the motivations of citizens who engage in open agriculture data hackathons. We conducted a case study and analyzed data collected from 161 participants of 11 farming hackathons held between 2016 and 2018 in the Netherlands. We found that participants of open agriculture data hackathons have different roles, including business developer, concept thinker, data analyst, data owner, developer, manager, marketer, problem owner, and student. Our analysis shows that citizens are predominantly motivated to engage in open agricultural data hackathons as part of their work. Furthermore, developers and problem owners are mainly motivated by fun and enjoyment. This indicates that it is important for open data policymakers and hackathon organizers to consider different approaches based on citizens' roles when organizing open data hackathons. This paper contributes to the literature by providing insight in the motivations of citizens engaging in open agriculture data hackathons in comparison with hackathons in other sectors, and by mapping citizens' roles to their motivations for engaging in such hackathons.