Improving the performance and, therefore, the profitability of expensive irrigation schemes is only possible with the dissemination of innovations for irrigated crop systems. As a social issue, technical innovations can be examined from different points of view, e.g., agronomists are studying how the technical references proposed by research are changed into agricultural practices. Working from a case study based on the analysis of the crop establishment phase for rice crop systems in Lake Alaotra, Madagascar, we show how action models can be used to explain the technical strategies and the adoption of new technology in a high risk situation. The formal identification of crop management practices highlights the links between technical, social and land risk management strategies. It also underlines the fact that resource-poor farmers are not in a position to really anticipate the different events that may occur. The framework proposed emphasizes the importance of non-climatic risks in the decision-making processes as well as inter-farm relation-ships. As a result, it calls into question the local development policy that focused exclusively on water supply and control.