Manejo de Tambaqui (Colossoma macropomum cuvier, 1818) em sistema aquapônico.

Abstract

Producing activity of aquatic organisms, aquaculture plays a fundamental role, aiming at the sustainable evolution of the food production of our planet. Aquaponics is one of the methods used to reduce environmental impacts by being a water recirculation system, where it integrates the best of aquaculture and hydroponics, producing high nutritional value protein, fish, which provide nutrients with the help of bacteria to vegetables without the use of chemicals or fertilizers. Thus, the present study aimed to evaluate the productive performance of juveniles of tambaqui (Colossoma macropomum Cuvier, 1818) and cultivars of jambu (Acmella oleracea) and lettuce (Lactuca sativa). Crop systems were characterized by NFT (Nutrient Flow Technique) composed of fish farming, vegetable growing and water treatment. The experiment lasted 90 consecutive days, being the first 25 days for sowing the jambu cultivars, and after transplanting to the canals, having 138 specimens of vegetables, where they remained for 30 days until the harvest period. After 5 days of jambu transplantation to the canals, lettuce germination started, remaining 25 days in the germination bank and after transplantation, remaining 30 days until the final phase. The system started with a total biomass of 810g. Subsequently, an extruded ration with 40% CP was offered daily three times a day (9, 13 and 17h). At the end of the experiment, the following fish production parameters were analyzed: initial average weight, final average weight; average weight gain; total biomass gain; apparent conversion of food; productivity and survival. The total length and weight of the fish were correlated by the potential equation Y = a * xb evaluated by Pearson's coefficient (r). For plants, the same parameters were analyzed except feed conversion. The physicochemical parameters of water (pH, electrical conductivity, dissolved solids, turbidity, temperature, ammonia, nitrite and nitrate) were monitored twice a week. The conductivity presented ideal values to those recommended for fish cultivation and lower for jambu and lettuce in hydroponics system. Already the temperature in the afternoon remained at high values in the water, out of the recommended in tambaqui fish farming, although the survival of 100%. The residual water from tambaqui cultivation was not able to meet the nutritional needs of plants by potassium in jambu, calcium and potassium in lettuce. Both species of vegetables presented higher values than recommended for copper. Finally, the average yield for fish was 3.63 kg/m3. As for jambu plants with 0.878 kg/m2 and lettuce with 0.658 kg/m2. Thus, through this study, it was found that the technique of integrating aquaculture with hydroponics has great promising potential in environmental and economic points.