Published in Scientific Papers. Series E. Land Reclamation, Earth Observation & Surveying, Environmental Engineering, Vol. V
Written by Ivaylo SIRAKOV, Katya VELICHKOVA, Stefka STOYANOVA, Desislava SLAVCHEVA-SIRAKOVA, Yordan STAYKOV
Two of the main parameters, which defined the cleaning capacity of cultivated plants and productivity of aquaponic systems, are the type of hydroponic compartment and plant’s growing media. The aim of current research was to compare the cleaning capacity and plant’s productivity of media bed and raft hydroponic sections as a part of a model aquaponic recirculation system. The impact of different plant growing mediums (cotton wool and rockwool) on lettuce yields was also retraced. For the purpose of this research two types of hydroponic sections (media bed and deep water sections) were constructed and integrated into an existing recirculation aquaculture system. For the trial 36 lettuce seedlings were used. Half of the plants were transferred to cotton wool and the other half of the lettuce plants were transferred to rockwool (Grodan®) substrates and afterwards all plants were placed in hydroponic pots. Eighteen lettuce seedlings (half planted on cotton wool and the other half on rockwool (Grodan®) substrate) were planted on the hydroponic section filled with lightweight expanded clay aggregate (LECA) and the other eighteen plants (half planted on cotton wool and the other half on rockwool (Grodan®) substrate) were planted on the floating raft hydroponic section.The hydrochemical parameters were measured during the trial. At the end and middle of the trial the fresh weight of lettuce plants was measured.A better removal capacity in ammonium, nitrate and ortho-phospahte were observed in the LECA section compared with the cleaning capacity in the raft section as a part of experimental aquaponic system. The raft technology showed better plant productivity compared with the one found for the LECA bed technology. The productivity of lettuce plants is highly dependent on the type of plant growing medium, when they are cultivated in the floating raft technology.
[Read full article] [Citation]
