Résumé
In Guinea and Madagascar, rice cultivation plays a central role in the country's food security. 80% of farms in these countries produce rice, and Guineans and Malagasy consume 110 and 120 kg of rice per capita per year, respectively. Fish is also the main protein consumed in Guinea, at 24 kg per capita per year, whereas fish is a rare food in Madagascar. Indeed, on this island, the population can consume only 4 kg of fish per inhabitant per year, compared with a world average of 10 kg per inhabitant.Rice-fish farming is an Asian model that can improve both rice and fish production and two notable initiatives seem to be spreading in Madagascar. The complexity of this system creates challenges for testing and identifying innovations that could improve its efficiency. One of the obstacles to optimizing the rice-fish system lies in understanding how it operate, which makes it difficult to optimize through conventional agricultural interventions. In light of this context, the study explores the internal mechanisms of these systems: their biological, technical or spatial complexity, and the inter- and intra-regional variability in agricultural performance. The results are discussed in terms of the usefulness of mobilizing farmer experimentation and co-design in the search for agroecological intensification of rice-fish farming systems.Our research indicates greater emphasis on co-designing agrifood systems research in South Asia is required to increase the resilience and sustainability of smallholder production systems, and the effectiveness of investments by donors and governments and increase. Smallholder farmers must be supported to incorporate new management practices to ensure these are scaled effectively and rapidly, thus maximizing the value of research and the investments underpinning it. This approach has important learnings for researchers, donors and policymakers, particularly across South Asia where methods of effectively scaling interventions have not been sufficiently widely incorporated into domestic and international research agendas.