ASSESSMENT OF THE INFLUENCES OF RAINFALL PATTERN SHIFTS ON RAINFED CEREAL CROP PRODUCTION UNDER CLIMATE CHANGE IN SNNPR, ETHIOPIA.

Abstract

Rainfed agriculture, representing 95% of cultivated land in Ethiopia, is exceedingly susceptible to the effects of climate change. The investigation analyzed the spatiotemporal fluctuations and patterns of rainfall and temperature, alongside the onset, cessation, and length of the rainy season from 1990 to 2021. Furthermore, it assessed the consequences of changes in rainfall and temperature on the production of major cereal crops such as teff, wheat, barley, maize, and sorghum between 2003 and 2021. Metrics like the Precipitation Concentration Index, Coefficient of Variation, and Rainfall Anomaly Index were computed. An innovative trend analysis technique (ITA) was applied for trend detection and validated using Mann–Kendall and Modified Mann- Kendall tests. Sen's slope estimator was used to assess the magnitude of rainfall trends, which were then incorporated into multivariable regression models to analyze the influence of rainfall and temperature on crop yield variability. The study revealed varied rainfall patterns in the Belg season, with 42.86% high, 42.86% moderate, and 14.255% low, and less variability in the Kiremt season, with 14.26% high, 14.26% moderate, and 71.43% low. Annually, 87.7% of rainfall shows moderate concentrations, with 14.255% exhibiting irregular concentrations in the southern part of the study region. Seasonally, the Belg rainy season demonstrates moderate concentration, while both the Kiremt and Belg seasons indicate low concentrations, moreover, 1.43% is slightly wet, 64.23% is close to normal, 24.29% is slightly dry, and 10% is moderately dry season have been seen for the period 2012-2021. ITA analysis exhibited statistically noteworthy increasing and decreasing trends in five stations, while MM-K analysis pointed out significant upward and downward trends in seven out of 14 stations. In the bimodal zone, intermittent rainy seasons and shorter days occurred from early March to late November, while in the unimodal zone, longer rainy days persisted from early March to late October. The influence of rainfall and temperature changes on crop yields varied among agroecological zones. In the Moist Sub-Humid Zone, climate variables had a weaker impact, explaining only 1-5% of yield variability. Conversely, in the Sub-Humid Zone, climate factors accounted for 12-14% of yield variability, indicating a stronger relationship. The results emphasize the need for implementing sustainable and adaptable agricultural practices, including crop diversification, agroforestry, soil and water management, and the adoption of climate-resilient crop varieties. These measures are essential for enhancing the resilience of rainfed cereal crop production in response to climate change.