Effect of Drip and Surface Irrigation Methods on Yield and Water Use Efficiency of Onion (Allium Cepa L.) under Semi-Arid Condition of Northern Ethiopia

Abstract

Water has been identified as one of the scarce inputs, which can severely restrict agricultural production and productivity unless it is carefully conserved and managed. It is a wide-ranging practice using every drop of water for crop production through suitable irrigation practices. Hence, a field experiment was conducted at Axum area (Northern Ethiopia) during the dry season of 2013 to 2014 using drip and furrow methods of irrigation to evaluate the effect of irrigation methods in combination with and without deficit irrigation practices on yield and water use efficiency (WUE) of onion under drip and surface method of irrigation. Four irrigation treatments viz., drip irrigation at 100, 80 and 60% crop evapotranspiration (ETc) and full furrow irrigation. Drip irrigation at 100% ETc gave significantly higher onion yield (28.0 t ha^-1), as compared to 80 and 60% ETc and furrow irrigation treatments. The onion irrigated at 100% ETc with drip method also registered 32.8% of increase in yield over furrow method of irrigation. However, irrigation water use efficiency was found highest (7.60 kg m^-3) with drip irrigation at 60% ETc and lowest (4.75 kg m^-3) with furrow irrigation. The amount of water saved at 100, 80 and 60% ETc under drip method was 29.4, 43.5 and 57.6 % respectively over furrow method and this would be sufficient to irrigate 0.42 to 1.36 a hectare of additional area of onion crop in which this earns better economic returns as compared to that of furrow irrigation method. Therefore, the study suggests farmers in the semi-arid conditions, having limited amount of water for irrigation, should adopt drip irrigation method instead of surface irrigation methods.

Keywords: Deficit irrigation, increase in yield, water saved, water use efficiency