How can we continue to keep food production viable for ourselves and at the same time for our planet in a world where natural resources are becoming scarcer? One possible answer to this question can be aquaponics, a unique method of growing food that uses the normal functions of plants and fish to produce large amounts of food in compact spaces.
If you're an urban folk you most probably have already appreciated the availability of fresh fruit and vegetables on the market coming from local farms and greenhouses. But what if we tell you that the supply of fresh vegetables on your table every day is thanks to fishes? In fact, everything from vegetables and herbs to beans and legumes can be grown in aquaponics, which offers an environment that is particularly suitable in urban settings where land is limited and demand for greens high.
Roman Gaus, a Swiss farmer and founder of UrbanFarmers, describes the concept of aquaponics in a simple way: “a method of combined fish and vegetable farming that requires no soil. The farmer cultivates freshwater fish (aquaculture) and plants (hydroponics) in a recirculating water system that exchanges nutrients between the two. Wastewater from the fish serves as organic fertilizer for the plants, while the plants clean the water of fish faeces and urine”. In exchange, the plant purifies the water which goes back to the fish. The result is a natural symbiosis and self-sustaining ecosystem.
Because this type of farming doesn’t need soil, a well-designed aquaponic system can be installed and run almost anywhere, including in densely populated urban environments. The high rooftops of parking lots are just a few examples of many places where aquaponics systems can work. Interestingly, compared to conventional fish farming methods, aquaponics uses 90 % less water and requires significantly fewer nutrients to feed the same amount of fish.
Fruits and vegetables can be grown efficiently without the need for pesticides or other synthetic chemicals that could affect the environment and human health when used in conventional agriculture. Indeed, only one ‘input’ (fish food) and no polluting ‘outputs’ such as CO2 emissions or waste to affect neighbouring land. Last but not least, the food coming from the aquaponic farm is of high quality and could satisfy both vegetarians and pescatarians.
The biggest problem is that it excludes plants such as carrot, potato or radish because of the lack of soil. also, a lot of power is necessary to keep a constant temperature in order to keep the fish alive. Finally, the capital expenditure of aeroponic system is higher compared to a traditional garden. Nevertheless, the full potential of aquaponics is yet to be explored with the tremendous opportunity for optimization offered by IoT technologies!