Sustainable intensification (SI) is promoted as a rural development paradigm for sub-Saharan Africa. Achieving SI requires smallholder farmers to have access toinformation that is context-specific, increases their decision-making capacities, andadapts to changing environments. Current extension services often struggle toaddress these needs. New mobile phone-based services can help.

This policy brief shows how digital tools can help to ensure that public money for agricul-tural extension is spent wisely. Governments often fund offices, training centers, and the salaries of extension officers, but cannot eas-ily review the impacts of these expenditures. This is because the activities of extension agents are not monitored systematically. Ex-ension services rarely generate quantitative data on the effects of their work.

Agricultural extension in the Global South can benefit greatly from the use of modern information and communication technologies (ICT). Yet, despite two decades of promising experiences, this potential is not fully realized. Here, it is reviewed the relevant research literature to inform future investments into agricultural information services that harness the full potential of digital media.The study describes a recently emerging innovation agenda that is, in part, a response to the eventualfailure of many new agro-advisory initiatives.

How do the innovation platforms and facilitated networks currently deployed in the Global South help trigger dynamics of collaborative innovation that can be useful for the agroecological transition? What are the difficulties encountered and how can they be overcome? This chapter throws lights on these questions. The first part justifies the interest in studying the ecologisation of agriculture through the prism of collaborative innovation and of its paradoxes.