The relationship between agriculture and biodiversity divides opinion among farmers. Our research proposes to describe and interpret these opinions, with regard to the diversity of the social backgrounds of the producers, with the hypothesis that interactions with local, non-agricultural individuals help shape these opinions. From 14 interviews carried out with farmers engaged in actions to preserve biodiversity in three territories in the West of France, we identify four different occupational conceptions, characterized by knowledge and taking natural entities into account, through the values and vision of the role that farmers intend to play with regard to biodiversity and way in which they would like this issue to be handled by society. While the role of peer networks in the construction of job conceptions is well established, our research shows that understanding the attitudes of agricultural professionals today requires a consideration of the role that experience and interactions with those outside the agricultural professional sphere play.