ABSTRACT
The vast African continent has many areas where crops can produce large yields. In the large wet tropical and savanna climate zones rainfall is abundant, while options for irrigation in drier zones are limited. Currently, yield gaps are large because actual crop yields are low mainly since soils do not supply sufficient amounts of nutrients. There are no other options than to fertilize with N, P, K and other nutrients to boost production. For N, despite the role which legumes can play, local production facilities of fertilizers are urgently needed. Local green urea production may be the much-needed breakthrough technology. Countries differ in their ability to meet food demand by intensification and expansion of agricultural area, and regional food trade is required for regional food self-sufficiency. A substantial proportion of smallholder farmers is unlikely to adopt the required technologies, reducing the agricultural area that can be intensified and implying that other farmers need to increase yields even more to limit the further expansion of agricultural land. Sustainable intensification is urgently needed but also increases greenhouse gas (GHG) and other emissions. However, compared to alternatives, this is the best available option especially when combined with strongly improved agronomic practices. Policies to support sustainable intensification, including local fertilizer production, should go hand-in-hand with legislation to control emissions and protect biodiversity.
