N2Africa was launched ten years ago in 2009. It was the first project funded by the Bill & Melinda Gates Foundation that focused on crop management. Up to that date the Foundation’s projects were largely based around crop breeding and biotechnology, or on markets and fertilizer supply.

To build on their earlier work, we started with the best grain legume varieties the breeders had available – but we needed to match these with the best rhizobium strains available. These needed to be tailored to the diversity of environments and farming systems across the countries where N2Africa would be working. All the earlier research indicated that good agronomic management was key to achieving good legume yields.

So we had the legume genotype (GL) interacting with the rhizobium genotype (GR), tailored to the environment (E) with a focus on best management (M). This became the core focus of N2Africa: (GL × GR) × E × M.

Our vision from the very start was to Put nitrogen fixation to work for smallholder farmers in Africa, putting the very best technologies available into the hands of farmers and to learn by doing. The main research question was “What works where, when, why and for whom?” We addressed it by testing technologies, working with thousands of farmers.

Closely monitoring and analysing outcomes, and combining fundamental and applied research, let us work along the technology pipeline looking for continuous improvement and refining our approach.

Along the way, we have collected a huge amount of information that is available in many forms of extension materials, newsletters, videos, radio programmes, project reports, and MSc and PhD theses. However, there was no one place where we had an overview of everything N2Africa has done. This collection of articles fills that void and gives a flavour of the excitement and the richness of the lessons learned from N2Africa.

Our funding from the Bill & Melinda Gates Foundation ended in June 2019, but much still remains to be done. We would like to thank the foundation for putting faith in us. N2Africa became a major part of the lives of many farmers, extension workers, scientists and others involved in rural development. We would like to thank them too for their partnership and commitment that is letting the activities continue in many forms.

Ken Giller Wageningen University and Research

Bernard Vanlauwe & Fred Kanampiu

International Institute for Tropical Agriculture