Collectives for exchanging practices to green agriculture: shedding light on the difficulties of a voluntary approach.

Summary Farmers' collectives provide a privileged space to support the adoption of green agronomic practices by building and sharing knowledge. However, a small proportion of farmers are formally involved in such groups. After an analysis of their contributions, with farmers who are members of technical collectives, we wonder about what helps establishing and making work a collective, through the feedback of a technical institute, on a critical project put on hold. Presented by the project promoters as the consequence of a lack of confidence from the farmers, the analysis of this failure is a source of learning. It highlights the difficulties and challenges of forming collectives, which are considered a major ingredient in transition discourse.