In aquaponic cultivation, plants utilise nutrients produced by fish directly from water, and no nutrients are released into the environment. The method has been used for a long time both in Finland and abroad, and it is easily scalable from at-home solutions to industrial halls, as long as there is sufficient growth area for plants. Food could be grown this way in, for example, restaurants and care facilities.
Although there’s been plenty of interest in the “plant factory”, the cultivation method is still awaiting its breakthrough in Finland. Finding the right balance has been a problem, because many things affect the nutrient balance of water and, consequently, the growth and health of fish and plants.
“Previously, we have studied the nitrogen cycle in co-cultivation of fish and plants. Now, for the first time, we are also studying the carbon cycle,” Researcher Harri Kokko from the Department of Environmental and Biological Sciences says. He has been studying vertical farming in urban settings for many years.
Indeed, the University of Eastern Finland is home to plenty of expertise in the plant sector, covering different plant species and their coexistence, nutrient needs, and optimisation of growth conditions. The cycle of various compounds is also modelled by using stable isotope analysis.
“It is possible to achieve a fully closed carbon cycle if conditions can be optimised.”
“We already have an idea of how to make the cycle work,” Research Manager Japo Jussila says. His responsibility in the study pertains to fish.
With a new continuous system, data is collected six times per minute. The database contains information on the amount and ratio of nitrates and ammonium, water temperature, and acidity. The fish are migratory whitefish, and the plants are nettle and basil.