Aquaponics is an integrated system where nutrients derived from aquaculture are used for plant growth and contribute to wastewater bioremediation. Although research with Euterpe precatoria in aquaponic systems has not been reported, providing information on its adaptation may support the development of viable systems. The aim of the present investigation was to evaluate the adaptation of E. precatoria seedlings in an aquaponic system with P. brachypomus, analyzing nutrients in the effluents and plant performance, after 120 days of cultivation.
Three treatments were established with 15 replicates (n=15); each replicate consisted of one plant: (T1) seedlings in soil substrate; (T2) and (T3) seedlings in two aquaponic systems that were irrigated with effluents from P. brachypomus farmed under a feeding rate of 2% (T2) and 5% (T3). Each aquaponic unit consisted of a 600 L tank with 30 fish (280.00±0.28 g) + mechanical filter + biological filter + hydroponic bed with 15 plants in an NFT system + final sump. After the hydroponic component, T2 and T3 did not modify (p>0.05) the physicochemical parameters of the irrigated effluent, but reduced the P content (p<0.05), indicating that this nutrient was used by the plants. A higher Ca and Mg content was observed in T1 soil substrate compared to the aquatic effluents, although no use of these nutrients and N by the plants using effluents was verified. The absence of mortality in the plants indicated their adaptation, although growth was not significant after the trial between the treatments (p>0.05). Additionally, plants in aquaponic systems presented conductive bundles defining the primary structure of the monocotyledonous stem, while plants in soil substrate presented only leaf primordia forming a false stem.
This pioneering research demonstrates that E. precatoria is capable of adapting to an aquaponic system by using P and showing histological modifications in the stem.