Direct sowing mulch-based cropping systems (DMC) have been disseminated in Madagascar since ten years. They meet environmental conservation, income generation and poverty alleviation objectives, especially in zones under the constraints of strong population growth, land scarcity, environmental and resources degradation, and unsustainable traditional farming systems. The Alaotra Lake region, has seen substantial DMC dissemination in recent years through a local development project BV-LAC. The approach taken by the project is intended to combine DMC dissemination with socio?territorial actions such as land certification, access to credit, marketing of agricultural products, input supplies, assistance for livestock production and pastures management. The project takes into account the complexity of local agrarian systems as well as farmers' diversity. Several farms categories were thus identified in a typology using the following main differentiation criteria: rice self-sufficiency, size of the farm, access to the different units of the physical environment, crop diversification, and off-farm activities. The implementation of a "farming system reference monitoring network", associated with farming system modelling with the software " OLYMPE ", enable to assess the economic impact of a technical choice for the different types of farms. Prospective analysis is done in order to identify the best bet alternatives and assess risk through climatic events or prices volatility. There are no categories that are completely "resistant" to DMC systems, but the degree of adoption can vary depending on i) the type of advantages or the response to a particular constraint and ii) the ability to implement these new technologies: integration with livestock, securing income on upland beside irrigated areas, relation between risk rating and investment capacity, access to markets....By taking these different elements into consideration, it's possible to improve significantly the dissemination efficiency. (Resume d'auteur)