In the ECOWAS region, agriculture plays a key role in the economies of member countries. It contributes 17.5% (World Bank) to the Gross Domestic Product (GDP) and employs more than half of our working population. Agriculture is the main source of income and employment for the population, the majority of whom live in rural areas. In Senegal, agriculture has in the past experienced a structural problem linked to the steady decline in its contribution to GDP. Our work is structured in three parts. The first chapter, on the methodological and theoretical framework, will consist of defining the scope of the study, i.e. presenting the study area and the investigative approaches and techniques, defining the problem and setting out the research objectives and hypotheses. The second chapter analyses the national onion market. In the final chapter, our study will focus on the financial and economic analysis of the establishment of our production farm.