Abstract
Background
Saline aquaponics is an integrated system that involves growing fish and crops in salt water. With freshwater scarcity increasing globally, saline aquaponics utilizes abundant saltwater resources, providing a sustainable solution for agriculture in arid and semi-arid regions. The sandponic system, utilizing sand for filtration and crop growth, conserves water and withstands environmental challenges. However, their performance under different salinity levels needs detailed study. This study compared the growth of lettuce plants grown in sandponic system under various salinity levels and examined the impact of saltwater on the biochemical parameters and growth of lettuce. This three-month study integrated a sandponic system into an existing aquaponic setup and primarily investigated the growth of lettuce (Lactuca sativa) and Tilapia fish (Oreochromis niloticus). Various conditions were tested, including tap water (control) and different levels of salinity (2.5%, 5%, and 10%). In the study, fish growth parameters remained unaffected by rising salinity, with all groups achieving a 90% survival rate.
Results
Elevated salinity showed potential efficiency gains in fish farming, as evidenced by better feed intake, weight gain, and feed conversion ratio in experimental groups. Lettuce growth thrived in freshwater, with promising results in 2.5% and 5% saltwater conditions, but 10% saltwater had a detrimental effect. Proximate composition analysis of lettuce indicated declining nutritional elements with increased saltwater, especially in the 10% group. Macro and micro mineral analysis showed no significant changes due to saltwater inclusion.
Conclusions
The introducing low levels of saltwater into irrigation systems does not adversely affect lettuce yield or nutritional quality. This finding supports the feasibility of integrating seawater into agriculture in coastal regions, provided salinity is carefully managed.