Evaluating the Efficiency of Hydroponic and Aeroponic Plant Nutrient Utilization Systems for Growing Tomatoes in Salinized Fishpond Wastewater

As the world's population continues to grow, addressing food insecurity is increasingly urgent. In this context, soilless farming techniques such as hydroponics and aeroponics have gained significant attention as promising solutions to food security challenges driven by population growth. This study aimed to evaluate the efficiency of nutrient utilization in nine pilot-scale hydroponic and aeroponic tomato cultivation systems using saline fishpond effluent as the nutrient source. The experiment was conducted from November 2020 to February 2021 at the Revi Tech facility within the Department of Botany and Microbiology, Faculty of Science, Suez Canal University, Ismailia, Egypt. Saline fishpond effluent served as the nutrient medium for tomato plants grown in both hydroponic and aeroponic systems. The primary components of the saline wastewater were analyzed, and two concentrations, 2000 and 3500 mg L-1 were used in the study. Physiological maturity of the tomato plants was assessed by measuring biomass, dry weight, shoot and root lengths, flower and fruit counts, and fruit weight. Mineral analysis was conducted to determine nitrogen, phosphorus, and potassium contents in different plant organs. Regarding nutrient utilization efficiency, the results revealed significant variation in plant measurement taken across the cultivation systems. The aeroponic system achieved the maximum shoot length of 130 cm, whereas the minimum shoot length (59.75 cm) was recorded in plants irrigated with 3500 mg L-1 saline effluent. Compared to hydroponic systems, aeroponic systems produced longer roots and higher nitrogen concentrations in plant tissues. When exposed to 2000 mg L-1 fishpond effluent, potassium content in aeroponically grown plants (7.92 g kg-1 dry weight) exceeded that in hydroponically grown plants (6.72 g kg-1 dry weight). A similar pattern was observed in fruit potassium content, with 7.05 g kg-1 and 5.20 g kg-1 dry weight for aeroponic and hydroponic systems, respectively. No significant differences were found in phosphorus levels among tomato plants grown in nutrient solutions or fishpond effluent at both tested concentrations (2000 and 3500 mg L-1).