Projecting nitrogen fertilizer use in Africa using empirically bounded historical drivers

Nitrogen fertilizer is critical for Africa's future food security. However, projections often describe trends without explaining what drives change or where uncertainty matters most. Here, we developed a data-driven framework to project nitrogen fertilizer intensity across 49 African countries using economic, biophysical, and structural drivers to determine whether, where, and how fertilizer could grow within historically observed constraints. We built five region-specific models using data-driven variable selection. We then generated optimistic, pessimistic, and business-as-usual pathways using a novel scenario design that varies influential, policy-relevant drivers within historical bounds. We find strong heterogeneity across countries: many countries, for example, Chad and Nigeria, remain at low fertilizer intensity, with only a handful of countries - e.g., Ethiopia and Namibia - showing substantial potential to grow their consumption. However, across all regions, all pathways remain approximately four to five times below an equitable-diet nitrogen benchmark. Agricultural intensification drivers dominate in East Africa, value and efficiency drivers dominate in North and Southern Africa, and intensification and labor-related drivers dominate in West Africa. Finally, we show where incremental progress may help and where deeper structural changes beyond historical precedents are needed to end fertilizer poverty and which drivers are key.