Sustainable intensification of smallholder farming is a serious option for satisfying 2050 global cereal requirements and alleviating persistent poverty. That option seems far off for Sub-Sahara Africa (SSA) where technology-driven productivity growth has largely failed. The article revisits this issue from a number of angles: current approaches to enlisting SSA smallholders in agricultural development; the history of the phenomenal productivity growth in the USA, The Netherlands and Green Revolution Asia; and the current framework conditions for SSA productivity growth.

This paper takes the viewpoint of a social scientist and looks at agricultural scientists' pathways for science impact. Awareness of these pathways is increasingly becoming part and parcel of the professionalism of the agricultural scientist, now that the pressure is on to mobilize smallholders and their productive resources for (global) food security and for reducing persistent rural poverty. Significant new thinking about pathways is emerging and it is useful to present some of this, even if it is not cut-and-dried.

The French Ministry of Agriculture has called for agro-ecological transitions that reconcile farming and the environment. In this review, we examine the transformations of farmers and AKIS (Agriculture Knowledge Innovation System) actors’ work during agro-ecological transitions, and argue that the content, organization, and aim of farmers’ work are influenced by agricultural training, agricultural development, and discussions between peers, research, and regulations. Our main findings concern those transformations.