The advance in agricultural technologies has allowed the development of innovative production systems; the aquaponics that allows the integration of aquaculture and hydroponic, increasing the profitability of the system. The intensive aquaculture recirculation systems, the main characteristic is that water exchange is minimum. The aim of the present was to evaluate the technical feasibility of using shrimp effluents (Litopenaeus vannamei) with low salinity (5 g/L) to irrigate tomato (Solanum lycopersicum cv Grape) under an aquaponics system supplying different concentrations of nitrates.
Four treatments were implemented with shrimp effluents compensating with synthetic fertilization of 0, 100 and 200 mg/L of KNO3-, the control was universal Steiner solution (SNS). The flow of water was continuous at a rate of 1 L/m. Completely randomized treatment was used in the aquaculture in the hydroponic with three repetitions. Tomato seedlings were at a density of 3.5 plants per linear meter, and shrimp densities were 100/m3. In the aquaculture system, weight, length, survival and mortality were evaluated, and in vegetative variable plants, and fruit production.
The physicochemical parameters were taken out of normal and final weight of shrimp were 18 g and survival 40% (Table 1).
Table 1. Growth indicators of white shrimp reared at experiment, and stocking at a density of 100 shrimp/m3.
The final production was 23.6 t/ha at irrigated with the SNS control, without differences to 200 mg/L NO3-. For the 0 and 100 mg/L-NO3-, production was reduced between 50-34%. The blossom-end rot of tomato is caused by water salinity (Fig. 2).
These procedures support to recycling of nutrients, which allows the constant reconditioning of water, since the integration systems the synthetic fertilizers are saved and the impact on the environment is minimized by aquaculture or hydroponic system water and waste discharges.