Variation in actual corn (Zea mays L.) evapotranspiration, single, and dual crop coefficient under different point source irrigation systems in a semiarid region

Abstract

Paying attention to irrigation of corn could have significant attention on water resources. The experiment was carried out to consider the influence of porous capsule irrigation (PCI), surface drip irrigation (DI) and subsurface drip irrigation (SDI) systems under mulch condition on actual evapotranspiration (ETc act), crop coefficients (Kc single and Kc dual), yield and water use efficiency (WUE) of corn in a semi-arid region of Iran. The experiment was arranged in a split-plot design with three irrigation systems as the main-factor and two soil coverage with mulch (M1) and nonmulch (M2) as sub-factor. The results showed that corn ETc act varied significantly with different irrigation systems (P<0.05), and was reported 389.8, 377.0 and 372.8 mm for PCI, DI and SDI systems, respectively. The highest value of Kc average and Kcb (0.82 and 1.22, respectively) and the minimum value of Ke (0.12) were seen in PCI system. The dry and wet biological yield were the highest in (PCI + M1) treatment (29.98 and 107 ton/ ha, respectively), and the lowest dry and wet biological yield were recorded in (DI+M2) treatment (23.19 and 58.54 ton/ha, respectively). The highest WUE (7.89 kg/m 3 ) were recorded in (PCI + M1) treatment. Using PCI system leads to higher biological yield, WUE and IWUE in comparison to DI and SDI systems. Accordingly, PCI system as an alternative to drip irrigation system can be a viable option for water scarce area particularly for smallholder farmers.