Maize Yield and Water Use Efficiency Under Different Irrigation Levels and Furrow Irrigation Methods in Semiarid, Tropical Region

Water scarcity is the major limiting factor of agricultural production and productivity in the central rift valley of Ethiopia. Best use of limited water is necessary through water conservation practices. Field experiments were conducted during the dry cropping seasons of 2016 and 2017 on clay loam soil at experimental farm of Melkassa Agricultural Research Centre to evaluate the impact of irrigated furrow methods and deficit irrigation applications on maize (Zea mays) yield and water use efficiency. The study involved three furrow irrigation methods (conventional, fixed, and alternate furrow irrigation) and three irrigation application levels (100%ETc, 75%ETc, and 50%ETc). Furrow irrigation system as main plot and irrigation levels as sub-plot were arranged in split plot design with three randomized complete blocks each year. Greatest yield was obtained under conventional furrow irrigation supplied with 100%ETc of water. Water use efficiency under the same treatment was lesser and shows no significant difference with fixed furrow irrigation and 50%ETc application. Greatest water use efficiency of maize was obtained from alternate furrow irrigation under 75%ETc application and showed no significant difference with 100%ETc application. However, grain yield reduction under 75%ETc applications was very much higher than 100%ETc application. Water saved as a result of 100ETc and 75%ETc applications were 50% and 62.5%, respectively. Therefore, scheduling irrigation time for maize in the central rift valley of Ethiopia and similar semiarid environments could be 100%ETc or 75%ETc application using alternate furrow irrigation. The 75%ETc application has an advantage over 100%ETc applications in saving more water and hence could be applied when water availability is severely limited.