Impacts of Climate Change on Bread Wheat (Triticum aestivum L) Yield in Adet, North Western Ethiopia

Abstract

Quantifying the extent and direction of climate change and its impacts is important on crop production as earth’s climate is undergoing changes. Thus the aim of this study was to assess the historical and future climate and its change impact on the yield of Tay and Senkegna bread wheat varieties in Adet, North Western Ethiopia. The observed daily climate data were obtained from National Meteorological Agency of Ethiopia, Bahir Dar branch for 33 years (1983 - 2015). Future climate data were from Climate Research Programme’s Fifth Coupled Model Intercomparison Project (CMIP5) database across 20 GCMs for RCP 8.5 emission scenarios in the time horizon of early-term (2010-2039), mid-century (2040-2069) and end-century (2070-2100). Soil data were obtained from Adet Agricultural Research Center. The onset, end dates, Length of Growing Period (LGP) and dry spell risk for the main rainy season were analyzed using first-order Markov model built in INSTAT tools version 3.36. Decision Support System for Agro-technology Transfer (DSSAT) crop model was employed during yield simulation. Onset of rainy seasons occurred before 1st decade of June was only 25% of the study years while it occurred before 2nd decade of June was 75% of the study years with coefficient of variation (CV) 5.3%. The end date of the rainy seasons occurred before 1st decade of November was 25% of the study years and occurred before 2nd decade of November was 75% of the study years with CV of 3.7%. Length of Growing Period (LGP) was ranged between 125-185 days with CV of 9%. The observed rainfall was decreased while both maximum and minimum temperatures were increased significantly (P<0.05). The projected maximum temperature is expected to increase by 1 to 4.69°C in 2030 to 2080. Furthermore, minimum temperature will increase by 0.93 to 4.73°C in 2030 to 2080. For Tay bread wheat variety, the grain yield is expected to increase by 0.5-1.3% in 2030 to 2050 but decreasing of 3% in 2080s. For Senkegna bread wheat variety, the yield is also increase by 1-2.3% in 2030 to 2080 relative to the baseline. However, days to anthesis and days to maturity of both wheat varieties will decline by 5-21% from the baseline.