Effects of different growth media on water quality and plant yield in a catfish-pumpkin aquaponics system

Abstract

Aquaponics production of fish and plant is one of the environmentally sustainable farming methods of the twenty-first century. In this study, two agricultural wastes (Palm kernel shells aka PKS and Periwinkle shells aka PWS) were evaluated for their suitability as growth beds in the propagation of pumpkin Telfairia occidentalis. In addition, conventionally used gravel and its mixture with PKS and PWS (33.33% each) were also tested. The resultant effects of these treatments on water quality of the system were reported. The result obtained reveals better performance of pumpkin in the PKS and PWS medias in terms of vine length, leave area, leave number, branch number and bi-weekly plant yield. The least performance was observed in the plants propagated in the gravel substrate. Water quality and percentage nitrogenous compound reduction (NH3, NO2 and NO3) across the system and in the different grow beds suggests that mixing all substrate resulted in better water qualities for fish and plant growth. Aside the superior growth observed in this study, alternative uses of these agricultural by-products in aquaponics system is highly recommended because of the possibility of converting waste to wealth.