BIOTECHNOLOGY OF JOINT AQUAPONICS FARMING OF AQUACULTURE AND AGRICULTURE OBJECTS USING BIOPREPARATION TO IMPROVE THE EFFICIENCY OF CROPS CULTIVATION IN THE ARTIFICIAL MULTI-TIERED SYSTEM

Development of new aquacultural and agricultural technologies plays significant role in the era of energy conservation and environmental priorities. Aquaponics is a technology that can provide population with natural and eco-friendly products. Fish and plants, cultivated via aquaponics technology, are currently covering only 7% of total Russia's food sector. However, in last several years this share is growing, forming a positive trend. During last two years, researches on the joint cultivation of hydrobionts and plants were held in an experimental aquacomplex of SSC RAS. These researches were embodied in the development of experimental integrated system of joint cultivation of hydrobionts and crops. The main goal was to create a biotechnology that allows to produce eco-friendly fish products and green plants via aquaponics method. Optimal aquatic and other parameters were defined and sustained in the integrated water supply system. These parameters were held in line with biological needs of all involved species and plants previously chosen for the experiment.

Bester (a hybrid of beluga and sterlet), clarion catfish and tilapia were farmed in the experimental system. During incubation process, high growth rates were reported. The survival rate indicator was at the point of 96-98%. After 4 months of Tilapia cultivation in a multi-tiered system, the average weight of each object was 194.14 ± 83 g while an average initial mass varied 21.26 ± 1.6 g. The absolute weight gain was 110.69 g, with the average daily increase of 1.7 g/day. Average daily growth rate was 1.3%, with the coefficient of mass accumulation 0.06 pt., and the Fultin's condition factor of 2.52 ± 0.15 pt.

The experiments on the joint cultivation of fish and crops such as tomatoes, cucumbers, bell peppers, strawberries, lettuce and parsley were conducted. Previous studies have shown that plants with a short growing period (45-60 days) are most suitable for farming via aquaponics method. Others with longer vegetative period accumulates an excessive amount of nitrates, exceeding MPC norms, which negatively influences the quality of the product. In this regard, the objective was to apply methods of growth stimulation and nitrate reduction for plants with a long growing season, such as tomato. A biopreparation based on the isolate of the Serratia ficaria strain were used during the experiment on tomato. The Serratia ficaria strain is not only restrains the development of pathogenic diseases in agricultural crops and stimulates plant growth, but also increases the concentration of vitamin C in fruits as well as reduces the accumulation of nitrates. Biopreparation based on the Serratia ficaria strain is completely safe for humans, animals and the environment. Treatment of plants with liquid form of Serratia ficaria was performed every 10 days. The obtained experimental data were compared with growth rates of plants from the control group. The liquid form of Serratia ficaria strain facilitates the intensive development of tomato. The increase in the length of the stalk in the experiment was 162.8% higher than in the control group. This indicates a significant stimulation of the development of agricultural plants during cultivation in water recirculation system using a preparation based on the Serratia ficaria strain. At the same time, the nitrate level did not exceed MPC norms during the experiment.