Effect of Furrow Length and Flow Rate on Irrigation Performances and Yield of Maize

Abstract

Furrow irrigation is the most widely practiced form of surface irrigation in the central valley of Ethiopia for cultivating different crops. This study was undertaken at Melkassa Agricultural Research Center to assess the effect of furrow length and flow rate on irrigation performance and maize yield using Melkassa II maize variety as a test crop. The experiment was designed in split plot with three replications, where furrow length used as the main plot and flow rate as sub-plot. The treatment includes furrow length of 16m, 32m, and 48m and flow rates of 0.52l/s, 0.79l/s, and 1.05l/s. The ranges of mean yield gained from furrow length and flow rate were 5.66 to 5.81ton/ha and 4.98 to 6.8ton/ha respectively. The effect of furrow length and their interaction with flow rate on yield were not significant (P=0.01) but the flow rate has significant effect on yield (P<0.01). The maximum yield was obtained from L3Q2(6.85ton/ha) but the minimum yield gained at L3Q2(4.85ton/ha). The range of mean crop water use efficiency from furrow length and flow rate was 8.30 to 8.53Kg/ha-mm and 7.3 to 9.98g/ha-mm respectively. The effect of furrow length on CWUE was not significant (P=0.01) but the flow rate has significant effect on yield and CWUE (P<0.01). The maximum and minimum CWUE was attained at L3Q2(10.02 Kg/ha-mm) and L3Q2(7.12 Kg/ha-mm) respectively. The highest and lowest measured values of Ea, DPR, SRR, Es, and DU range was 21.85 to 38.52%, 8.15 to 17.16%, 51.1 to 70.0%, 31.65 to 56.0%, and 29.67 to 78.3%, respectively. The irrigation performance indicators were significantly affected by both furrow length and flow rate. In a soil that has loam texture, 0.5% furrow bed slope, and a furrow length of 48m it is suitable to use 0.79l/s of flow rate for better maize yield, water use efficiency, and irrigation efficiency. Open-ended short furrows were the major source of water loss through surface runoff that has resulted lower adequacy of water in the crop root zone.