Abstract
Flow rate and furrow length are the main irrigation decision variables currently affecting yield and water productivity at farm level. Improper selection of these variables produces an over use of water and loss in crop production. The general objective was to investigate the effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system, with specific objective to analyze the effect of flow rate, furrow length and their interaction on yield and water productivity of onion. The field experiment was laid out in randomized complete block design with factorial arrangement of three levels of flow rate (0.7, 0.98 and 1.3 L/S) and three levels of furrow length (25, 35 and 50 m) with three replications. Inflow out flow method was used to determine the infiltration characteristics of the soil and Irrigation depth was controlled by using 3-inch Parshall flume. The maximum non-erosive flow rate to the experimental site was fixed through design equation considering soil textural class and furrow bed slope. Effect of furrow length and flow rate on yield and water productivity of the onion were used for evaluation. Their analyses indicated that effect of furrow length and their interaction with flow rate on yield were not significant (p<0.05). However, the flow rate showed highly significant (p<0.01) effect on yield of onion. The ranges of mean yield gained from furrow length and flow rate were F1 (14.75 ton ha-1) to F3 (15.96 ton ha-1) and Q1 (13.59 ton ha-1) to Q3 (19.69 ton ha-1), respectively. The effect of furrow length on crop water use efficiency and field water use efficiency was not significant (p<0.05). However, the flow rate has showed highly significant (p<0.01) effect on crop water use efficiency and field water use efficiency. The range of mean crop water use efficiency and field water use efficiency from furrow length and flow rate were F1 (33.65 kg/ha/mm) to F3 (36.41 kg/ha/mm) and Q1 (30.99 kg/ha/mm) to Q3 (38.65kg/ha/mm) and F1 (2.06 kg/m3) to F3 (2.23 kg/m3) and Q1 (1.89 kg/m3) to Q3 (2.36 kg/m3), respectively. Therefore, it can be concluded that a furrow length of 50 m is suitable to use 1.3 L/S of flow rate for better onion yield and water productivity under similar soil type of study area.
 Int. J. Agril. Res. Innov. Tech. 11(1): 92-100, June 2021
Highlights
Ethiopia has large agricultural sector and water potential
The minimum and maximum crop water use efficiency was obtained from the flow rate of Q1 (30.99 kg/ha/mm) and Q3 (38.65 kg/ha/mm), respectively
The maximum crop water use efficiency was obtained at higher flow rate (Table 6)
Summary
Ethiopia has large agricultural sector and water potential. Growing human population, recurrent drought and periodic floods, complicated with climate change that has been accompanied by severe soil and landscape degradation in some regions contributed to a situation of national food insecurity (FAO, 2011). Increasing population and competition for water due to the development of other water use sectors imposed the improvement of water productivity in irrigated agriculture to ensure sustained production and conservation of limited resource (Mekonen, 2011). In spite of its enormous potential to ensuring long-term food security in Ethiopia, irrigated agriculture is facing inadequate water management at farm level and poor irrigation efficiency. Inappropriate management of irrigation system has contributed, to food insecurity and to environmental problems including excessive water depletion, water quality reduction, water logging and salinization (Akinbile and Yusoff, 2011).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
