Assessing changes in climate suitability and yields of maize and sorghum crops over Kenya in the twenty-first century

Climate change has and will continue to affect food security in different dimensions. This study aims at comparing current and future maize and sorghum climate suitability and yield using five state-of-art climate models in the Representative Concentration Pathways (RCP8.5) in Couple Intercomparison Project Phase 5 (CMIP5). The study considered 1970-2000 as the baseline and 2040-2060 (the 2050s) and 2061-2080 (2070s) as the projection periods. The mechanist FAO Eco-crop model and statistical crop model were used. The results show that rainfall and temperature are projected to increase by 2050s and 2070s with certain (uncertainty) in temperature (rainfall) projection. The central and western highlands are the optimum suitable zones for maize. Gradual reduction of maize suitable zone is anticipated leading to a yield loss of 10.8% (23.7%) by 2050s (2070s). The sorghum climate suitable areas are expected to increase in the future leading to a yield gain of 114% (80.7%) by 2050s (2070s) from the baseline yield. Currently, temperature creates more uncertainties in crop yield than rainfall. The findings of this research enlighten the policymakers and farmers on the probable susceptibilities of the agricultural system in future climate and the viable strategic measures to curb food insecurity over the country.