PERFORMANCE EVALUATION OF UDO WETATE IRRIGATION SCHEME FOR WHEAT PRODUCTION USING FURROW IRRIGATION METHOD; IN SIDAMA REGION, ETHIOPIA

Abstract

Performance evaluation in irrigation systems plays a vital role in identifying the gaps and applying mitigation measures. The objective of the study was to undertake performance evaluation on winter wheat irrigation system of Udo Wetate irrigation scheme. For primary data collection field observations were conducted, discharge rates in the irrigation canals were measured, soil moisture content was determined, and the depth of water applied to the fields was also measured. For technical evaluation of the scheme using performance indicators, three sample plots were selected from the head, middle and tail-end of the main canal. The findings of this study revealed several performance issues with the Udo Wetate irrigation system. The irrigation water supply exceeded demand across all sample plots in February, ranging from 36.6% to 56.88% excess due to plot location and crop growth stage, but by March the supply only exceeded demand in two plots while falling short by 16.72% in the plot located at the canal tail, and by April crop water demands exceeded supply at all plots from 0.86% to 33% shortfall due to inadequate water application and conveyance losses. The conveyance efficiency was a major contributor to this inefficiency, with the main and tertiary canals having efficiencies of just 45.3% and 61.5% respectively. The mean field application efficiency was estimated to be 60.0%, which is considered good but had noticeable differences between plots due to different water application and relative location of plots from the source. The average storage efficiency was 50.8%, However, the distribution uniformity was 81.0%, indicating the irrigation water was fairly evenly distributed. Overall, the efficiency of the Udo Wetate irrigation scheme was found to be only 32.14% impacted by water management problems, insufficient water application, lack of awareness of crop water requirements, improper furrow design, and soil type, generally indicating moderate performance. Based on the results for this study non -proportionality of the irrigation water demand with supply, poor water delivery system, absence of frequent maintenance and management were problems strongly affecting the performance of the scheme. Therefore, it is suggested that frequent maintenance, giving training and applying a strong water delivery plan are required to mitigate this problem