THE EFFECT OF SUPPLEMENTARY IRRIGATION ON MAIZE CROP PRODUCTION UNDER RAIN-FED AGRICULTURE IN ARBA MINCH AREA, ETHIOPIA

Abstract

Supplementary irrigation increases and stabilized yield of rainfed agriculture. Substantial yield improvements could be achieved when supplemental irrigations are give to rain fed agriculture during critical growth periods .This research was undertaken to identify the effect of supplementary irrigation under rain-fed for maize crop, in order to provide necessary information in decision making on irrigation management. The experiment was laid out in aRCBD with three replication. The treatments include, a control (Rain-fed only) and three supplementary irrigations with 10, 25 and 50% ETc. The Supplementary irrigation was considers only during the critical water stress conditions due to inadequacy of rainfall and when soil moisture was below 20%.. All other cultural management practices other than supplemental irrigation were the same. Data analysis has shown significant difference among treatment for grain yield, plant height, leaf length, leaf width. The supplemental ir rigation with 50% ETc application gave the highest record for all parameters except for leaf area. Maize average yield under rain-fed was lowest (2.88t/ha) and significantly different to all other treatment. Whereas, under 10 and, 25%ETc supplementary irrigation maize yield was not significantly different to each other. . Supplementing rain-fed agricultural production system by 10% of ETc was increased the yield by 6% whereas, supplementing by 25 and 50%ETc during critical water stress periods was increased the yield by 17 and 39%, respectively. From the results of the experiment, supplementing rain-fed agriculture by 50%ETc during critical water stress periods maximizes yield and plant growth parameters observed.