The role of Deficit Irrigation in Enhancing Water Use Efficiency in garlic (Allium sativum) Production, Central Ethiopia's Tiyo District

Water scarcity poses a growing threat to agricultural productivity in arid and semi-arid regions like Central Ethiopia. This study evaluated the role of deficit irrigation (DI) and furrow irrigation systems in enhancing water use efficiency (WUE) and maintaining garlic (Allium sativum L.) yield under limited water conditions. A field experiment was conducted in the Tiyo District, comparing four irrigation levels (100%, 85%, 70%, and 55% of crop evapotranspiration, ETc) across three furrow irrigation systems: conventional (CFI), alternate (AFI), and fixed (FFI). The study followed a randomized complete block design with 12 treatments replicated three times. Results revealed that the highest yield (9862.4 kg/ha) was achieved under CFI100%ETc, while the highest irrigation water use efficiency (28.64 kg/mm) was recorded under AFI100%ETc. Moderate deficit irrigation (85% and 70% ETc) under AFI significantly improved both crop water productivity and water savings without a statistically significant yield loss. These findings demonstrate that AFI combined with moderate DI can optimize water use and sustain garlic production in water-scarce areas. The study provides evidence-based recommendations for improving irrigation practices to enhance agricultural productivity and resilience in regions experiencing water stress.