Assessing The Impact Of Rainfall Variability On Wheat, Barley And Teff Crops Production In The South Wollo Zone Of Ethiopia

Abstract

Variation in the seasonal cycle of Ethiopian rainfall is key importance for agriculture. This study was undertaken in South Wollo Zone, which is situated in the northeastern Ethiopia, to analyze the impacts of extensive seasonal rainfall variability on three wheat, barley and teff crops productivity. We use observed sea-surface temperatures (SST), satellite estimated rainfall data (CHIRPS), gauge-based observed rainfall from local meteorological stations and crop yields to explore crops productivity associated with warm phase of ENSO identified based on eastern Pacific SSTs. Standard statistical descriptors and statistical software like INSTAT V3.37, MAKESENS 1.0, XLSTAT 2014 and Arc GIS 10.3 were employed for the analysis. The results indicated that South Wollo Zone experienced moderate rainfall variability in kiremt (JJAS) season (CV=20%-30%) and high variability in belg (FMAM) season (CV>30%).The results indicated that the mean onset date of the main rain season (JJAS) for Akesta, Ambamariam and Wogdi station was 5th July and at station Haik, Tebasit and Worebabo was July 7th. Furthermore, the results of Pearson Correlation Coefficients indicated that duration of kiremt rainy season and kiremt rain fall total had strong positive, weak negative and weak positive relationship (r = 0.906, r = -0.203 and r = 0.344) with wheat, barley and teff respectively in Borena district of South Wollo Zone. The annual and seasonal rainfall trend results showed that South Wollo Zone practiced a decreasing trend. This study further showed that warm phases of ENSO are strongly related to recent droughts that induced significant crop yield reduction due to erratic and poor kiremt performance. Given that climate change is real, we suggest that recurrent and more extensive El Niño, which is responsible for recent droughts are likely to reoccur, thus we should document how historical rainfall trend explain crop yield variation so as to predict and respond to multi-year drought and substantial crop yield reduction in South Wollo Zone of Ethiopia.