Purpose: To promote sustainable agriculture, various development projects are encouraging farmers around Madagascar's Lake Alaotra to adopt conservation agriculture techniques. This article's objective is to analyze the capacity of a project-funded advisory system to accompany such an innovation and to design and implement an advisory method aimed at fostering learning processes for sustainable changes at the farm level. Design/methodology/approach: We used an analytical framework where three components are responsible for the advisory system's performance: the governance, including the funding mechanisms, the methods for generating advice and the capacities of actors involved in the provision of advice. We carried out surveys with the main actors involved in advisory services and with farmers involved in conservation agriculture. Findings: Results of the study highlight the current domination of technical advice dedicated to promoting conservation agriculture based on recommendations arising from agricultural research. Even if advisory actors show a willingness to promote advisory services which address the overall farm complexity, the results question the advisory method used and the ability of advisors to adopt an advisory system built jointly with the farmers. The farmers and farmers' organizations have a limited ability to influence choices made by the project. The results question the sustainability of the advisory mechanism in the context of external funding of the advisory system. Practical implications: The case study provides useful lessons for other projects funding advisory systems aimed at promoting conservation agriculture combining standard solutions for many farmers and learning process. Originality/value: The systemic approach at advisory system level to understand the advisory method in action is the main originality of the article.