Effects of Deficit Irrigation Scheduling on Water Use, Gas Exchange, Yield, and Fruit Quality of Date Palm

Abstract

Water scarcity is very common in the arid region due to the low yearly rainfall. The cost of water for agricultural usage is extremely high in dry locations. Date palm is a high water-demanding tree throughout the year in arid regions. Therefore, the application of deficit irrigation strategies for date palm cultivation may significantly contribute to conserving irrigation water. The present study aimed to assess the effects of controlled deficit irrigation using two modern micro-irrigation systems on water use efficiency (WUE), gas exchange, fruit yield, and quality of date palm (Khalas cv.). The irrigation systems included drip irrigation (DI) and subsurface irrigation (SI) systems. The study was conducted during the 2020 and 2021 seasons at the Date Palm Research Center of Excellence, King Faisal University, Saudi Arabia. The meteorological variables of the study area were real-time monitored using cloud-based IoT (Internet of Things) to calculate the evapotranspiration reference (ETo) and control the irrigation scheduling. Three irrigation treatments (50, 75, and 100% ETc) were applied using DI and SI systems compared with the traditional surface bubbler irrigation (Control). The actual applied water at the deficit irrigation treatments of 50, 75, and 100% ETc were 27.28 ± 0.06, 44.14 ± 1.07, and 55.55 ± 0.37 m3 palm−1, respectively. At all deficit irrigation treatments, the leaf chlorophyll and gas exchange were significantly higher in the SI compared to the DI system. The yield of date palms did not differ significantly between the control and SI systems at both the level of 100 and 75% ETc. The WUE under the SI (1.09 kg m−3) was significantly higher than the DI system (0.52 kg m−3) at the 50% level. There was no significant difference regarding the fruit quality parameters between SI at 50% ETc and control at 100% ETc. Therefore, adopting deficit irrigation strategies using the SI system at 50% ETc level throughout the year could be suggested for date palm irrigation to save water, improve WUE, and maintain fruit quality.

Effects of Automated Irrigation Systems and Water Regimes on Soil Properties, Water Productivity, Yield and Fruit Quality of Date Palm

“…Highest fruit yield and crop water productivity was reported in date palm cvs. Sheshi [42] and Khalas [41] when the trees were irrigated by the subsurface irrigation system at 50% ETc. Another study found that the date palm plant irrigated with a 60% water requirement in the SSDI system showed no significant difference compared to the bubbler system at 100% ETc [79].…”

“…Subsurface drip irrigation reduces subsurface drainage, manages soil salinity, and enhances tomato yield [40]. In addition, it is not affected by high wind velocity as the water is applied directly to plants' root zones [41,42]. Higher crop yields, saving of water, increased fertilizer use efficiency, reduced energy consumption, tolerance to windy atmospheric conditions, reduced labor cost, minimized pest and disease problems, suitability in sloppy lands, and improved soil tolerance to salinity are just a few advantages of subsurface drip irrigation system over other irrigation methods [10,29,[41][42][43][44][45][46].…”

“…In addition, it is not affected by high wind velocity as the water is applied directly to plants' root zones [41,42]. Higher crop yields, saving of water, increased fertilizer use efficiency, reduced energy consumption, tolerance to windy atmospheric conditions, reduced labor cost, minimized pest and disease problems, suitability in sloppy lands, and improved soil tolerance to salinity are just a few advantages of subsurface drip irrigation system over other irrigation methods [10,29,[41][42][43][44][45][46]. Although traditional surface irrigation systems produce the highest date palm yields by consuming more water [29,47], modern micro-irrigation systems can use less irrigation water and produce comparable yields [41,42].…”

“…It was also revealed that, compared to bubbler and drip irrigation systems, crop water productivity was significantly higher in subsurface irrigation systems at 50% ETc, which saved water and positively improved the physiological and fruit yield-related attributes of date palm cvs. Sheshi and Khalas [41,42].…”

Profiling of Water-Use Efficiency in Switchgrass (Panicum virgatum L.) and the Relationship with Cadmium Accumulation

“…Previous reports have demonstrated that Cd strongly inhibited the synthesis of chlorophylls and their stable binding to proteins, thereby damaging the photosynthetic apparatus and, in particular, decreasing the concentration of light-harvesting complex II and photosystems I (PSI) and II (PSII) [15,16]. Water is one of the crucial factors limiting crop production in numerous regions worldwide [17,18]. Other studies have indicated that increasing WUE can reduce water stress and improve productivity under stress [19,20].…”