Aquaponics versus conventional farming: effects on the growth, nutritional and chemical compositions of Celosia argentea L., Corchorus olitorius L., and Ocimum gratissimum L.

This study examined the practicality and sustainability of growing leafy vegetables in aquaponics instead of traditional soil-based farming systems by comparing the physiological growth patterns, nutritional compositions, and phytochemical constituents of Celosia argentea L., Corchorus olitorius L. and Ocimum gratissimum L. grown in aquaponics with those of other conventional systems. The results of this study indicate that the growth and accumulation of biomass by plants grown in aquaponics were similar to those obtained in unamended loamy soil but better than those of plants grown in inorganic hydroponics. However, plants grown in NPK-supplemented soil showed significantly (p<0.05) higher biomass accumulation than those grown in aquaponics. Likewise, C. argentea, C. olitorius, and O. gratissimum grown in aquaponics had significantly higher nutrient compositions than those grown in inorganic medium, and at the same time, similar to that of plants grown in unamended loamy soil. C. argentea and C. olitorius grown in inorganic medium had significantly higher concentrations of the observed phytochemicals than those grown in aquaponics, whereas the opposite was true for O. gratissimum. The three plant species were able to serve as filters for the effective maintenance of nitrogen dynamics in the constructed African catfish aquaponics, while utilizing nitrogenous waste for biomass production.