Résumé
CONTEXT: In the context of global change, large irrigation schemes are once again at the forefront of regional and national development plans. The Bagré irrigation scheme in Burkina Faso, with 16,780 ha planned, of which 3380 ha already under cultivation, is emblematic of this renewed interest. However, it is worth remembering that large irrigation schemes in sub-Saharan Africa have rarely delivered the expected benefits in terms of poverty alleviation and food sovereignty. A detailed analysis of the mechanisms at work can inform decision-makers about the risks of failure and how to prevent them. OBJECTIVE: Understand why, despite the near quadrupling of cereal yields in the Bagré irrigation scheme compared with the rainfed area around, there has been no progress in poverty reduction and food sovereignty. METHODS: To assess the contribution of this irrigation scheme to food and economic security, we compared the situation of 180 households on and off the scheme using a holistic approach. In-depth statistical analyses at the household level were combined with participatory analyses, using focus group discussions, the co-construction of food and economic security thresholds, and informal interviews. This helps to identify the underlying causes of the poor performance of this scheme and to discuss with stakeholders on solutions for enhancing their livelihoods. RESULTS AND CONCLUSIONS: 84 % of households in the irrigation scheme suffer from economic insecurity and 38 % from weak food security. Their situation is worse than that of households located outside the scheme (64 % and 25 %, respectively). This is mainly attributed to low access to off-farm opportunities and to irrigated land per worker: 0.30 ha, whereas at least 0.50 ha (or access to off-farm jobs) is needed to meet the needs of a worker and a dependent relative. If the high cost of land development (€15,000/ha) explains the allocation of small plots, the economic rationale for spending much money to keep people in poverty and in a more vulnerable situation than before is questionable. Environmental degradation is also significant (soil degradation, river pollution, and destruction of wildlife habitats). SIGNIFICANCE: This study contributes to the debate on the ability of large irrigation schemes to reduce poverty and increase cereal production. This is an important issue, as there is renewed interest in these schemes following the 2008 food crisis. In Burkina Faso, large irrigation projects remain a priority, and the Bagré irrigation scheme is undergoing expansion, without a larger land area allocated to beneficiary households.