Optimization of sustainable maize production in Sub-Sahara Africa using split-plot response surface methodology

This study investigated optimization of fertilizer on maize yield in Iburu and Zaria, Nigeria, where soils are nutrient-depleted and fertilizer efficiency is generally low. The objective was to identify site-specific optimum application rates of nitrogen (N) and phosphorus (P) across COMP1 SYN and IWD-C3-SYN-F2 maize varieties using Split-Plot Response Surface Methodology (SP-RSM). Secondary field data obtained from the International Institute of Tropical Agriculture (IITA) under the Transformation of agronomic research were analyzed using SP-RSM. The model incorporated linear, quadratic, and their interactions. Model adequacy was assessed using sequential sum of squares, lack-of-fit tests, adjusted R2 and predicted R2 values. The analysis revealed strong effects between nitrogen and phosphorus rate for increasing yield within moderate ranges. Of all the models considered, quadratic model outperformed others for yield of maize optimization within the study area which is confirmed by using adjusted R2 (0.670). Also, adequate Precision ratio of 24.389 confirmed model reliability and evaluation of all variety fertilizer combinations identified variety IWD-C3-SYN-F2 at 120 kg N/ha and 60 kg P/ha as optimum treatment combination with yield of 4538.311 kg/ha. The result provides evidence-based fertilizer recommendations that contributes to improved nutrient management strategies which can enhance maize production, food security, and smallholder farmer livelihoods in Nigeria. Hence, cultivation of IWD-C3-SYN-F2 will result in an increased grain yield and the application of 120 kg N/ha and 60 kg P/ha will also result in increased grain production.