Rising world demand for vegetable oil is reflected in the extension of oil palm (Elaeis guineensis Jacq.) cultivation in the tropics. In Africa, oil palm plantations are managed by both agroindustrial companies, which have their own oil mills, and by smallholders, who deliver their fresh fruit bunches to these industrial mills, or process their own production on a small scale. In southern Cameroon for example, oil palm smallholdings have been booming since the mid-1990s to reach about 40,000 ha of selected palm plantations (Rafflegeau et al, 2010). The sustainability of smallholding production therefore mainly depends on the durability of soil mineral fertility (Hartley 1988). Technical advice disseminated to smallholders from the beginning of the smallholder development programme was often extrapolated from estate practices, which differ greatly from those of smallholders, in terms of previous plant cover, intercrops, cover crops, fertilizer applied, etc. (Cheyns & Rafflegeau, 2005). Whereas a partnership already exists between agronomic Research and agroindustrial companies, Cameroonian smallholders are facing a lack of research programmes and technical advice well suited to their specific conditions. The need for this kind of support will only be met if a strong partnership is co-built between agroindustrial companies, smallholders, and researchers.