Effect of Deficit Irrigation on Maize (Zea Mays L.) Crop Under Conventional, Fixed, and Alternate Furrow Irrigation for Effective Irrigation Water Management

A study was conducted with the objective of determining the effect of deficit irrigation on maize (Zea mays L.) under conventional, fixed, and alternate furrow irrigation. The experiment was conducted at Jimma Agricultural Research Center (JARC) in 2014/2015 and 2015/2016 dry periods. Nine treatments of different deficit irrigation levels were factorial combined and randomized in plots, and all cultural practices were done. The crop water requirement was calculated using the CROPWAT8.0 program. Yield and growth parameter data were recorded, and analyzed using SAS software. The two-year over-all statistical analysis result showed that, different deficit irrigation levels had a significant effect (p<0.05) on grain yield, ear height, fresh biomass, 100 seed weight, girth, and water productivity. However, there was no significant effect (p > 0.05) on plant height and internode length. The result revealed that 100% ETc conventional furrow gave the highest grain yield (106.1 Qun/ha), followed by 75% ETc conventional furrow (101.23 Qun/ha) and 50% ETc conventional furrow (81.86 Qun/ha). The minimum yield of 55.64 Qun/ha was obtained at a fixed 50% furrow irrigation, and there was a 52.44% yield improvement. The maximum fresh biomass of 196.5 Qun/ha was obtained from 100% conventional furrow, and the minimum 103.40 Qun/ha was at 50% fixed furrow irrigation. The maximum and minimum water productivity of 8.007 and 2.8 kg/m3 were obtained at 75% conventional and 100% fixed furrow irrigation, respectively. Considering the water productivity, net economic benefit and sustainable production of the crop in the agroecology of the study area, combination of 55% up to 85% of deficit irrigation level with conventional furrow irrigation system could be recommended for the production of maize in a deficit furrow irrigation method. Based on the observations made and the statistical analysis done, fixed furrow irrigation was not recommended for the study area.