Résumé
After the extensive droughts of the mid70s in the Sahel, the construction of the Diama and Manantali dams materialized the will of the Senegalese State to develop the Senegal River Valley region. From 2010 the government accelerated the pace to economically valorize these investments by implementing an ambitious national program of rice self-sufficiency. However, that rapid irrigated rice expansion added to the drought and pushed back the natural floods, endangering the traditional culture system of flood recession in the main riverbed, the Waalo. But the traditional flood recession cropping system is low in inputs: not as labour-intensive as rice (direct planting) and rich in biodiversity, in particular for sorghum. The DIVA project, was conducted in Guédé-Chantier and 2 surrounding villages (Podor Department) and was carried out within the Halpulaar society, the majority in the middle valley. It aimed to comprehensively describe the consequences of these transformations for the agricultural, social, gender and nutritional dimensions. Considering that the convergence of academically distinguished research objects could be better achieved by associating research with various actors involved in local life, thanks to the mediation of the NGO Enda Pronat local peoples, the experimentation in the reality of transdisciplinary was also a scientific objective of the study discussed in this paper. So we applied a gendered transdisciplinary approach to consider three interconnected dimensions: social and family logics, agricultural management of biodiversity and diet quality. Results show that women's initiatives to improve and diversify their diet in response to rice pressure, essentially consisted of organic or non-organic collective irrigated gardeners, established with the help of NGOs but without any technical or financial support from the public policies. Nevertheless, we assessed that the current diet quality of the women was of concern, with an overconsumption of cereals (white rice) to the detriment of other plant-based foods and animal products. Simulations of the dietary changes that have occurred over the past 45 years showed that the diet quality has deteriorated with a significant decrease of nutrient intakes such as thiamin, vitamins B-6 and B-12, iron, potassium and zinc. We conclude that the rice intensification is increasing pressure on the flood recession system, which, by disappearing, increases food and environmental problems. Facing these deteriorations, the management of local agricultural biodiversity initiated by women is diverse and localized but limited and not so far supported by any governmental policy.