Closing maize yield gaps in sub-Saharan Africa will boost soil N2O emissions

•Maize yields in sub-Sahara Africa are low due to low fertilizer input.•This creates a yield gap (difference between potential and actual maize yield).•Closing yield gaps will increase area-based but not yield-scaled N2O emissions.•Increased fertilizer use can reduce pressure on natural lands. In sub-Saharan Africa (SSA), the most important staple crop is maize; the production of which is dominated by smallholder farming systems using low external inputs (