Assessing agricultural anaerobic digestion in agroecology: a case study from Brittany, France

Since 2013, French public authorities and consultancies have promoted agricultural anaerobic digestion as crucial for transitioning to agroecology. This article examines whether this process truly aligns with agroecological principles, focusing on environmental, social, and economic sustainability. Based on extensive fieldwork and interviews in Brittany’s Rennes and Gouessant Basins, findings indicate that biogas units produce significant changes, especially in farms with high energy-to-farmland ratios. Several agronomic limitations were uncovered, including increased maize acreage, reduced biodiversity during intercropping, shorter rotations, and higher input use. Economically, anaerobic digestion primarily benefits project promoters, exacerbating inequalities among farmers and showing limited impact on job creation.