Potential impact of climate change on drought-tolerant maize varieties and nitrogen fertilization in Nigeria savannas: a decision support tool (DST) analysis

Purpose Nitrogen fertilization is a crucial factor in sustainable agriculture practices because it enhances the resilience of maize crops to climate change. This study aims to quantify location-specific adaptation measures to climate change using drought-tolerant maize varieties and N fertilization in the savannas of Nigeria using the Agricultural Production Systems Simulator (APSIM) model. Design/methodology/approach The calibrated APSIM-maize module was validated using an independent dataset from field experiments conducted under different N fertilization levels within savanna agroecological zones (AEZs). The impacts of climate change were assessed under low and high emissions representative concentration pathways (RCPs), 4.5 and 8.5 W m2 scenarios, for the near-term (2010–2039) and mid-century (2040–2069). Findings The study found that the yields of early and medium maturing maize varieties decreased under climate change scenarios. For the early variety (2009EVDT), yields decline by 1–4% under RCP 4.5 and 3–8% under RCP 8.5 in the near term, and 2–12% under RCP 4.5 and 1–12% under RCP 8.5 mid-century. For the medium variety (IWDC2SYNF2), grain yield decreases were 1–5% under RCP 4.5 and 2–11% under RCP 8.5 near-term, and 1–8% under RCP 4.5 and 3–14% under RCP 8.5 mid-century. Applying N-fertilizer at 90–120 kg ha−¹ can minimize these effects across the three AEZs. Practical implications This study supports strategic nitrogen fertilization and drought-resistant maize varieties to maximize yields and ensure food security under climate change. The government and relevant agencies should strengthen policies to help farmers adopt adaptive strategies to cope with projected high temperatures and droughts, to enhance sustainability. Originality/value The originality of this paper stems from the contributions of the various authors: Conceptualization, A.B., A.Y.K. and J.M.J.; methodology, A.B., A.Y.K. and J.M.J.; validation, A.B., A.Y.K. and A.I.T.; formal analysis, A.B. and F.M.A.; field experimentation, A.B. and A.I.T.; resources, A.Y.K. and J.M.J.; data curation, A.B., A.I.T. and F.M.A.; writing original draft preparation, A.B., A.Y.K. and F.M.A.; writing review and editing, A.B., A.Y.K., J.M.J, A.I.T. and F.M.A.; supervision, A.Y.K., J.M.J. and F.M.A.; funding acquisition, A.Y.K. and J.M.J. All authors have read and agreed to the published version of the manuscript.