灌漑・排水システム工学

Water availability is becoming a critical issue in Ethiopia so that preferable irrigation technologies need to be developed and water productivity of irrigated crops through water management is a vital option in water scarce areas. Hence, the objective of this study was to enhance potato tuber production through the application of different irrigation system and deficit irrigation application under highland climatic condition. Field experiment was carried out at farmer field of Oda Sirba scheme for three consecutive years with three furrow irrigation system and one deficit irrigation 80% ETc and control irrigation 100% ETc replicated three times in a split plot design. Obtained results revealed that, the highest seasonal water requirement value of 497.8 mm was at CFI with full irrigation application while, the lowest value of 199.2 mm was by AFI and FFI with 80% ETc. The analysis of variance indicated that there was significant (P ≤ 0.05) difference obtained for yield and WUE of potato tuber. The highest yield of 36.12 t ha-1 was obtained from control treatment with CFI while FFI at deficit application had the lowest yield of 26.3 t ha-1. The nearest yield of 34.22 t ha-1 was obtained by AFI method with full irrigation application. Higher water use efficiency was observed at AFI method at a control level with 13.75 kg m^-3 and higher than at 80% ETc with 13.46 kg m^-3 but there is no significant variation between them. Highest benefit cost ratio of 47.85 was obtained from AFI method at control level. Yield and water use efficiency based comparison had shown that there was significant difference between the yield and WUE obtained at AFI and CFI, while applied water in AFI was reduced by 50%. Therefore, it can be concluded that increased water saving and associated water productivity through the use of AFI with 100% ETc, can solve problem of water shortage which improve WUE without significant reduction of yield. AFI system at full irrigation application appears to be a promising alternative for water conservation and labor saving with negligible reduction in yield.