EFFECT OF SMART IRRIGATION CONTROLLERS UNITS ON THE PERFORMANCE AND PRODUCTIVITY OF SUBSURFACE AND SURFACE DRIP IRRIGATION SYSTEMS FOR TOMATO CROP IN ARID REGIONS

Two types of Smart irrigation controller units  (SIC) for scheduling irrigation water were studied   under Saudi Arabia’s present water crisis scenario. They were oprated based on evapotranspiration rate (ETR) promising tools for scheduling irrigation requirement by means of quantifying water required by plants to targeted water savings. The purpose of this study is to evaluate the effectiveness of these technologies, i.e. SmartLine and Hunter on irrigation amount applied, and compared with conventional irrigation scheduling methods as a control treatment. These two types of smart irrigation were implemented and tested under surface drip irrigation (DI) and subsurface drip irrigation (SDI) for tomato crop (Nema tomato cv.) in arid region. The obtained results showed that there are significant differences in the amount of applied water and the yield for the three irrigation scheduling methods. The data were normalized to produce a tomato crop yield per mm water depth applied, providing values of 66.50 (48.91), 62.74 (47.75), and 35.54 (28.21) kg/mm for the Hunter, SmartLine, and control systems, respectively, under SDI and (DI). The results also revealed  that plant the growth parameters and water conservation were significantly affected by Hunter controller and  SDI. The irrigation water use efficiency (IWUE) under Hunter controller under SDI was generally higher (15.92 kg m^-3) as compared with  that under control DI (6.76 kg m^-3), resulting in maximal IWUE for both growing seasons (average 15.82 kg m^-3). The application of Hunter controller under SDI technology therefore provides significant advantages in terms of both crop yield and IWUE. In addition, Hunter controller under SDI conserves 25% of the total irrigation water as compared with the control treatment, and simultaneously generates higher total yields. Generally, it can be mentioned that Hunter Pro-C system saved more water and produced more yield with the highest use irrigation efficiency (IWUE) under SDI compared with the other irrigation scheduling methods. Moreover, the results indicated that the SDI system produced a higher yield and IWUE than DI. Ultimately, these technology is recommended for efficient automated irrigation systems and the Hunter Pro-C technique may provide a valuable tool for conserving water planning and irrigation scheduling for tomato and which is extendable to other similar agricultural crops.