Production of tambaqui juveniles (Colossoma macropomum) and arugula microgreens (Eruca sativa) in small-scale aquaponic systems: technical and economic viability

Aquaponics is an activity that has been growing worldwide as a sustainable alternative for food production and practical implementation throughout society. The objective of this study was to develop micro-scale aquaponics with a native Brazilian species, the tambaqui (Colossoma macropomum), associated with the cultivation of microgreens, an agro-food trend, using arugula (Eruca sativa), with the aim of evaluating the economic viability of family production. For 70 days, the growth performance of 80 tambaqui juveniles (average initial weight = 61.88 g ± 8.31 g) was monitored. Two treatments with two hydroponics structures, Nutrient Film Technique (NFT) and Floating Raft Technology (FRT), each with four replications, were compared. Tambaqui survival was 100% in both treatments. The final weight of juveniles was 136.38 g (± 35.67 g) in NFT systems and 116.5 g (± 24.63 g) in FRT systems. In the four production cycles carried out, the arugula microgreens performed better in the NFT systems (157.38 g ± 21.74 g; 6.68 cm ± 0.17 cm) compared to FRT (41 g ± 6.18 g; 4.46 cm ± 0.58 cm), identifying the best hydroponic unit for the cultivation of E. sativa microgreens. Finally, the economic viability study was conducted considering the average wage in Brazil of US$ 285.66 for the implementation of a homemade aquaponic system. The possible scenarios considered a family income of two or more minimum wages for the implementation of at least one aquaponic system.