Trends and impacts of climate variability on maize (Zea mays) yield in Adami Tulu Jido Kombolcha, Central Rift Valley of Ethiopia (1981-2018)

The impacts of climate change are of great concern for Ethiopia and other developing countries whose population is dependent on subsistence agriculture, a climate-sensitive sector. This study is intended to analyze the trends and impacts of climate variability on maize yield in Adami Tulu Jido Kombolcha, Central Rift Valley of Ethiopia. Meteorological data spanning from 1981 to 2018 were obtained from Ethiopian Meteorological Institute while crop yield data were collected from Adami Tulu Jido Kombolcha Agriculture Office. Climate variability was analyzed using coefficient of variation, standard deviation, standard rainfall anomaly and precipitation concentration index. Trend was tested using Mann-Kendal (MK) and Pearson's correlation and multiple regression model were employed to see the effects of climate on maize yield. The results revealed that annual rainfall shows a declining trend of 1.89 mm/year and its pattern and distribution become irregular. On a seasonal basis, Belg rainfall declined at a rate of 2.28 mm. Annual maximum, minimum and mean temperature shows a warming trend of 0.02, 0.04 & 0.04 degrees C, respectively, in the study area. The warming trend detected during Belg (February to May) is statistically significant for both maximum and minimum temperature. In addition, the maize yield shows a decline of 0.08 quintals per year in the study area. Rainfall is more responsible for maize yield reduction than temperature. Therefore, this study suggests access to extension services, irrigation practices, and the selection of drought and heat resistant crop varieties to smallholder farmers.