Research can only make genuine contributions to farmers' productivity if it is carried out in close association with them, testing technologies as much as possible under their management and in their own fields. This chapter brings together the main features and evolution of soil fertility research in and for sub-Saharan Africa (SSA). It scrutinizes these and other lessons emerging from the work described in the preceding chapters, which hopefully can help current and future researchers to avoid the pitfalls of the past and increase their chances to contribute to the improvement of agricultural production in Africa. These two components, characterisation and the development of prototype technology, were in fulfilment of the original goal of international research, of generating information for and providing innovative technological components to the National Agricultural Research Systems (NARS), for further adaptation and eventual transfer to the farmer through the extension service. The role of partnerships has undergone fundamental changes over the years.