Effect of different hydraulic loading rates on growth of basil (Ocimum basilicum L. ‘Genovese’) in nutrient film technique aquaponics

Abstract

Aquaponics are promising and sustainable technologies consisting of fish-plant-bacteria consortia in the same system, thereby providing an environmentally friendly system by recycling water and nutrients. This study was planned to investigate the influence of varying hydraulic loading rates (HLR) on the growth of basil plant (Ocimum basilicum L. ‘Genovese’) in a low-cost of electricity nutrient film technique aquaponics (NFT) integrated with African catfish (Clarias gariepinus (Burchell)) under the Eastern Mediterranean climate conditions, Antalya, Türkiye. The hydraulic loading rates tested in plant-growing troughs 2, 4, 8, and 12 m3/m2/day. African catfish showed an excellent feed conversion ratio (0.695) over the experiment. There was no statistically significant difference in plant height, number of leaves, and stem diameter for basil plants, but a statistically significant difference was found in plant weight and leaf area. The best plant weight gain was observed in the 4 m3/m2/day group with 23.0±2.5 g mean weight. The optimum HLR for basil production was estimated as 4.41 m3/m2/day based on yield (kg/m2) and energy consumption (KWh/kg basil) in a basil-African catfish integrated NFT aquaponics. The optimum HLR can maximize production without further increase of energy expenditure. Higher HLRs of 4.41 increase energy cost per unit of basil production.