Smallholder farmers across the Global South increasingly need to adapt their farming activities to fast-paced changes, for example, in climate, policy and markets. In many places, public and private agricultural extension services support technological change through trainings and the dissemination of information. The effectiveness of extant ex-tension (advisory) methodologies is, however, challenged by the difficulty of reaching a large and growing clientele with highly diverse information needs.

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.

Rapid climatic and socio-economic changes challenge current agricultural R&D capacity. The necessary quantum leap in knowledge generation should build on the innovation capacity of farmers themselves. A novel citizen science methodology, triadic comparisons of technologies or tricot, was implemented in pilot studies in India, East Africa, and Central America. The methodology involves distributing a pool of agricultural technologies in different combinations of three to individual farmers who observe these technologies under farm conditions and compare their performance.

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.

This article examines how research on the agriculture and agrifood systems mobilizes the concept of Innovation System (IS). A literature review on the IS provides an analytical framework for determining its theoretical frame of reference, its area of application and its uses.