Growing food without soil is an increasingly popular way to farm. This week on Friday Night Feast, Jamie and Jimmy take a look at aquaponics, so Daniel Nowland, Head of Jamie’s Technical Food team, explains what it is and how it works.
Over the past century, our food production system has changed enormously. Much of our farming has moved from small, skilled growers to multimillion-dollar industries that specialise in one or two crops. While these large-scale industries can produce seemingly cheap food for consumers, the loss of diversity is taking its toll on the environment. As well as making use of a waste product, aquaponics offers a potential solution to loss of diversity.
What exactly is aquaponics?
Put simply, it’s a method of feeding and growing crops using the by-product from fish farming. It might sound odd, but this is something that’s been happening in nature forever. Uncontaminated waste from humans, animals or fish is nature’s most efficient fuel for new plant life. We’re all familiar with horse manure being spread onto allotments and flower beds, right?
Aquaponic systems grow salad, veg or fruit in trays, which are fed by a flowing cycle of water. As part of the cycle, the water passes through a tank of fish, and it carries with it waste from the fish. This fish waste is a concentrated mix of nutrients and minerals, which are absorbed by the plants.
What are the benefits?
Aquaponic systems have only one ‘input’, which is feed for the fish – no other fertilisers or chemicals are needed for the plants to flourish. Meanwhile, there are also no ‘outputs’, other than edible food. As the system is self-contained, there is no runoff of chemicals onto neighbouring land – and no negative impact on waterways or wildlife.
Because this type of farming doesn’t require soil, aquaponic systems can be created anywhere – warehouses, underground, or on roofs of buildings.
The quality of the food is incredible. Thanks to the nutrient-rich input and careful attention, the crops are delicious. Plus, as well as growing a variety of healthy salads, the system produces a small amount of edible fish, when the fish stocks are replenished with younger fish.
Are there any negatives?
One downside is that not all crops can be grown this way yet. At present, fast-growing, leafy crops work best in these systems.
Meanwhile, some people argue the system isn’t natural as the plants aren’t grown in soil. But, did you know that most tomatoes, cucumbers and peppers grown in Europe are not in fact grown in soil, but in manmade substrates, fed by nutrient-enriched water?
While we agree that soil is nature’s most versatile substrate for growing in, it’s important to understand that healthy soils are under threat, thanks to climate change and the effects of industrial-scale farming in recent decades.
How do I find out more?
Aquaponic producers are popping up in various places, including central London. Some supermarket chains are even thinking of using their roof space for these systems in the future. In Friday Night Feast, Jamie and Jimmy visit an aquaponic producer in the West Country, who grows in greenhouses.
There are various producers across the UK who are selling their products to local restaurants, as well as direct to consumers through farm-drop schemes. At the moment, you won’t find aquaponic-grown food on supermarket shelves in the UK, but it’s probably only a matter of time.
Watch this week’s Jamie and Jimmy’s Friday Night Feast to see the boys delve deeper into the world of aquaponics. Catch the show every Friday at 8pm on Channel 4.