Effect of treated wastewater irrigation on ornamental plants: Case study of Lantana and Hibiscus, Morocco

In water stressed countries such as Morocco, the use of treated wastewater represents a strategic perspective for sustainable agricultural development. However, technological and management innovations are needed to make it feasible and effective. The main objective of this work is to evaluate the effect of irrigation with treated wastewater compared with fresh water on the growth of two ornamental plants: Rosa Sinensis hibiscus and Lantana Camara. The study also aimed to examine the impact of treated wastewater on the hydraulic performance of different irrigation systems. To carry out this study, irrigation was applied by two irrigation systems: subsurface drip irrigation and surface drip irrigation. Also, two sources of water were compared: treated wastewater from the WWTP of M'zar (tertiary treatment) and well water, each for a duration of 2 months. The results obtained showed that the treated wastewater generally promoted a better development of agronomic parameters such as height, number of branches, leaves, and flowers for both plants. The same observation was also made regarding the esthetical parameter. For the irrigation system effect, the results obtained showed a better development under the subsurface drip irrigation system; thus, the combination of treated wastewater and subsurface drip irrigation provided the best results for both plants. Regarding the hydraulic performance of the irrigation system, no risk of clogging of the distributors was observed in relation to the water quality; the uniformity coefficient and distribution uniformity remained above 90%. It can therefore be deduced that the use of treated wastewater for irrigation of green spaces should be at the heart of water resource mobilization policies. in fact, it represents an excellent alternative for promoting national water management strategies.