Abstract:
In countries like Ethiopia where agriculture is dependent on rainfall, the impact of climate
change on crop production is large. Understanding impact of climate change at local level and
specific crop is of paramount importance. The aim of this study was to characterize climate
change and model its impact on barley production in Welmera District, Ethiopia. Accordingly,
historical climate data (1986-2016) was collected from Holeta Agricultural Research Center to
analyze the past climate of the study area. In addition, future climate was downscaled from an
ensemble of two climate models (CSIRO-Mk3-6-0 and HadGEM 2- ES) using MarkSim weather
generator for the medium (RCP 4.5) and higher (RCP 8.5) emissions trajectory. INSTAT+v.3.36
software and the Mann-Kendall test and Sen’s slope estimator were employed to assess trends of
rainfall and temperature variables. DSSAT V4.7 was used to simulate future change in barley
yield (Holker and HB-1307) and to identify best adaptation measures in the study area. The
results of this study revealed that both annual and seasonal rainfall showed a decreasing trend
in the last three decades. In contrast, both maximum and minimum temperature exhibited an
increasing trend for monthly, annual and seasonal rainfall. The annual minimum and maximum
temperature has shown an increasing trend with a magnitude of 0.004 and 0.04 0
C per year
respectively. On the other hand, projected annual and seasonal rainfall showed an increasing
trend except in bega season by 2050’s under both time of slices and RCPs. More increment of
rainfall will be expected in belg as compared with kiremt and bega seasons under both time of
analysis and RCPs. Moreover, mean annual and seasonal maximum and minimum temperature
projected to increase under both time slices and emission scenarios. The crop model simulation
indicated that projected climate will have negative consequences on the yield of Holker variety
except by 2080’s under RCP 8.5 while positive consequences on HB-1307 variety in both time
slices and RCPs scenarios. Hence, Climate change could affect the production of barley in the
study area in different time slices both in the past and in the future climatic conditions. As
adaptation measures, planting windows of 15th June for Holker variety and 4thJuly for
HB-1307variety found to be best adaptation measure. Planting density of 169 plants m-2 for
Holker and 195 plants m-2 for HB-1307variety expected to increase the yield under projected
future climatic condition of the study area. Therefore, adopting appropriate agronomic practice
might reduce the impacts of climate change on the yield of barley in the study area.
