STOCKING DENSITY INFLUENCES ECONOMIC FEASIBILITY AND YIELD IN A GIFT (Oreochromis niloticus) AND FODDER MAIZE (Zea mays) BASED AQUAPONIC SYSTEM

GIFT and FODDER MAIZE BASED AQUAPONICS

Abstract

The present study revealed the effective stocking density of fish required for economic feasibility in an aquaponic system. In a 75 days trial, GIFT (Oreochromis niloticus) in an aquaponic system was stocked with fodder maize (Zea mays) with four different stocking densities i.e. 100 nos./m3, 200nos./m3, 300nos./m3 and 400nos./m3 with fodder maize as plant component in hydroponic beds at 400plants/m2. In control (T0) fishes were stocked with 100nos./m3 in triplicates where plants were planted outside with the same density. It was observed that the SGR was highest in T1 and least in T4. The result showed that with an increase in stocking density up to 400nos./m3 the survival rate decreases due to higher stocking density and high ammonia load in the culture tank. But the total yield of fish was found to be higher in T3 (1281.93 ± 17.34g). Growth indices of fodder maize (Zea mays) such as plant height, height gain, percentage height gain, plant growth rate and yield were recorded highest in T4 and least in control (T0) which might be due to the availability of more fish waste and nutrients accumulated in the system for plants with higher stocking densities of fish. The economic evaluation showed highest benefit-cost ratio (BCR) in T3 (1.77) and the lowest in T4 (1.23) which might be due to the higher stocking density and survivability of fish which helps in more yield of both fish and plants. Hence, the results indicate that with optimum of 300 nos. of GIFT/m³ in combination with fodder maize at 400plants/m² will be economically viable for farming practices in an aquaponic system. culture in mild-acidic pH exposure was recorded underlining the significant role of water pH on the growth and survival of M. rosenbergii larvae.