Assessing the use of a drought-tolerant variety as adaptation strategy for maize production under climate change in the savannas of Nigeria

Abstract

The Decision Support System for Agricultural Technology Transfer (DSSAT) was used to quantify the impact of climate change on maize yield and the potential benefits of the use of drought-tolerant maize variety over non-drought tolerant variety in savanna ecological zones of Nigeria. Projections of maize yields were estimated for three locations representing different agro-climatic zones and soil conditions, in the mid-century (2040–2069) and end-century (2070–2099) under representative concentration pathways scenarios (RCP 4.5 and 8.5) against the baseline period (1980–2009). Relative to the baseline period, the ensemble Global Circulation Models (GCMs) predicted significant increase in minimum and maximum temperatures and seasonal rainfall across the sites. In the mid-century, ensemble GCMs predicted temperatures increase between 1.7–2.4 °C for RCP4.5 and 2.2–2.9 °C for RCP8.5. By end-century, the temperature increases between 2.2–3.0 °C under RCP4.5 and 3.9–5.0 °C under RCP8.5. Predicted seasonal rainfall increase between 1.2–7% for RCP4.5 and 0.03–10.6% for RCP8.5 in the mid-century. By end of century, rainfall is expected to increase between 2–6.7% for RCP4.5 and 3.3–20.1% for RCP8.5. The DSSAT model predictions indicated a negative impact on maize yield in all the selected sites, but the degree of the impact varies with variety and location. In the mid-century, the results showed that the yield of the non–drought tolerant maize variety, SAMMAZ-16 will decline by 13–19% under RCP4.5 and 19–28% under RCP8.5. The projection by end-century indicates a decline in yield by 18–26% under RCP4.5 and 38–47% under RCP8.5. The yield of the drought-tolerant variety is projected to decline by 9–18% for RCP4.5 and 14–25% for RCP8.5 in the mid-century and 13–23% under RCP4.5 and 32–43% under RCP8.5 by the end-century. The higher temperatures by both emission scenarios (RCP 4.5 and 8.5) were primarily shown to cause more yield losses for non-drought-tolerant variety than that of the drought-tolerant variety. There will be 1–6% less reduction in yield when drought-tolerant variety is used. However, the higher yield reductions in the range of − 13 to − 43% predicted for the drought-tolerant variety by the end of the century across the study areas highlighted the need to modify the maize breeding scheme to combine both tolerances to drought and heat stresses in the agro-ecological zones of northern Nigeria.

Extreme Weather Events Affect Agronomic Practices and Their Environmental Impact in Maize Cultivation

“…We emphasize that all hybrids used in the study belong to a similar maturity group (sown and harvested at the same time); therefore, the result of the higher yield potential was a response to a genetic trait. This is in line with previous studies from different parts of the world [74][75][76][77][78], where authors agreed that future research should involve modifying the maize selection criteria to combine tolerances to both drought and wet condition stresses.…”

Evaluating the use of nitrogen and phosphorous fertilization as crop management options for maize adaptation to climate change in the Nigeria savannas

“…Although increasing N resulted in increased yield when P was applied, the yield response of maize to N application was less under future climate conditions compared to baseline yield (figures S1-3). The general yield reductions may be attributed to the increases in temperatures since the models projected increase or no change in rainfall depending on the location of the study (Tofa et al 2021). Previous study also revealed that an increase in air temperature might affect maize growth and development (Abraha and Savage 2006, Meza et al 2008, Tachie-Obeng et al 2013.…”

“…Four contrasting bias corrected GCMs (CESM1-CAM5, CSIRO-MK3.6.0 HadGEM2-ES, and MRI-CGCM3) from Fifth Coupled Model Inter-comparison Project (CMIP5) were used in for the analysis. Detailed about the four GCMs and changes in rainfall and temperatures based on GCM outputs have been reported in Tofa et al (2021). The climate change impact assessment was carried out by comparing the simulated yield of two maize varieties using the baseline climate data against the simulated yield for the midcentury climate data (2040-2069) and end of century (2070-2099) periods under RCP4.5 and RCP8.5 scenarios.…”

“…There are current and projected reports on the impact of climate change in Nigeria, either in the form of increasing temperatures or drought (Adefolalu 2007, Olapido 2010, Blanc 2012, Omotosho et al 2014, Amanchukwu et al 2015 which would negatively affect maize productivity. In the Nigerian savannas, Tofa et al (2021) predicted temperatures would increase by 2.2 °C-2.9 °C in the mid-century and up to 3.9 °C-5.0 °C by the end of the century under RCP8.5 scenario. The models also predicted increase in rainfall in the drier Sudan savanna and a reduction in the Guinea savannas (Tofa et al 2021).…”

“…To mitigate the adverse impacts of climate change, many adaptation technologies have been proposed. This includes the use of improved crop management practices like nitrogen fertilizer application (Kassie et al 2015), planting date manipulation (White et al 2011), supplementary irrigation (Kassie et al 2015, Araya et al 2017, and the deployment of drought-tolerant varieties (Bänziger et al 2006, Tesfaye et al 2018, Tofa et al 2021. In the Central Rift Valley of Ethiopia, increasing nitrogen fertilization has been demonstrated to reduce the detrimental impact of climate change by increasing maize grain yield (Kassie et al 2015).…”