Evaluation of Desalinated Water Efficiency for Irrigating Tomato Plants under Arid Conditions in Farms of the Wadi Zamzam Region - Libya

Abstract

The limitation of water resources and the high salinity of irrigation water are among the most important factors affecting agricultural production in arid and semi-arid regions, which requires searching for alternative water sources such as desalinated water. This study aimed to evaluate the efficiency of desalinated water for irrigating tomato plants under arid conditions in farms of the Wadi Zamzam Region, Libya, compared with different irrigation water sources, through studying vegetative growth, yield components, productivity, water use efficiency, and some chemical properties of the soil. The field experiment was conducted using a Randomized Complete Block Design (RCBD) with four irrigation treatments and four replicates, including groundwater well water (EC = 3.80 dS/m), desalinated water (EC = 0.34 dS/m), mixed water at a ratio of 50:50 (EC = 2.07 dS/m), and highly saline groundwater (EC = 7.49 dS/m). The results showed the superiority of irrigation with desalinated water in all studied characteristics, where the plants recorded the highest values in plant height, number of leaves, number of branches, and stem diameter compared with the other treatments. Desalinated water also achieved the highest values for yield components, as the average number of fruits reached 39.75 fruits/plant, fruit weight was 97.11 g, plant productivity was 3.84 kg/plant, and crop productivity per unit area reached 78.65 tons/hectare, exceeding highly saline water, which recorded the lowest values. Desalinated water also increased water use efficiency to reach 15.41 kg crop/m³ water, compared with the use of highly saline water, which reduced water use efficiency to reach 6.74 kg crop/m³ water. Chemical analyses showed that desalinated water reduced salt accumulation and improved soil properties, growth, productivity, and water use efficiency, while highly saline water caused deterioration in soil properties and a decrease in production. The study confirms that the use of desalinated water represents a promising option to support agricultural production and improve tomato productivity in arid regions with good irrigation and fertilization management to ensure agricultural sustainability.