Growing food without soil: feeding the world with aquaponics


Most people are prepared to admit that there are a lot of serious problems facing the world today.

How we manage these issues, and the resulting effects on our planet, has a huge impact not only on the economy but also our own wellbeing. As a society, we are resource hungry. But a lot of people are just hungry.

The population bomb

The world population has more than doubled since 1960 and is now 7 billion people and rising. It’s expected to reach nearly 10 billion people as soon as 2050, with some estimating a peak as high at 15 billion by the end of the century. Wherever and whenever the peak comes, it will inevitably then slow up and even go into decline. Most western countries are already experiencing slow or negative growth.

The trouble is, 10 billion people is A LOT of people, especially since this rise in numbers will also mean a shift to a more resource intensive diet. More people means more middle classes, and more middle classes mean moving from simple and predominantly vegetable-based diets towards more highly processed, meat-heavy western diets. The problem? It takes 13 lbs of grain to produce just 1 lb of meat.

We need to start finding ways of reducing our resource consumption whilst still continuing to meet our needs.

Resource challenges

Two of the key resources are productive topsoil and water. With dwindling access to potable water and topsoil shortages in many areas, the question is  burning one: just how are we going to feed 10 billion people? It’s a big ask.

Although it doesn’t look like we have a silver bullet to solve this problem in a single hit, there’s a lot of exciting and innovative work going on around new technologies and food production techniques to try and find some answers.

Aquaponics is one of these technologies.

An introduction to aquaponics 

Aquaponics research projectNever heard of it? What if I told you that people are using aquaponics to produce food in the desert? That we can now produce crops using just 2% of the water that would normally be used? And that we’re not only produce plants, but protein too? You’ve got to be at least a bit intrigued…

Welcome to the world of aquaponics. Aquaponics uses a fully contained closed-loop sustainable growing system which requires limited resources. It combines recirculating aquaculture with hydroponics to enable us to use nutrient waste as an input to plant growth. In English? We’re feeding fish, collecting the poo, then feeding the plants with the fish poo. Is it glamorous? No. Does it work? Undoubtedly yes.

The system basically mimics nature – where waste from one species is food for the next. And it’s not even that technologically advanced. We grow fresh water fish in tanks, then convert their waste into nutrients which feed the plants (using naturally occurring bacteria). By taking up the nutrients the plants in turn clean the water, which is then recirculated back to the fish tank. The only water loss is through evaporation and transpiration: with none of it seeping away into the ground.

There are some incredible people and projects leading the charge with this amazing technology. Like the Kickstarter campaign which raised nearly $250,000 to produce home aquaponics kits, or this US based non-profit using aquaponics to help ensure local communities have access to safe, healthy and affordable food, or the company Bioponica which is dedicated to innovating new more sustainable modular farming systems.

But can aquaponics feed the world?

Aquaponics has huge potential, but there’s a lot we still don’t understand. Like any new technology, it takes time to work out the best approach before we can effectively scale up. That said, we are already seeing some commercial aquaponic operations and there are large numbers of backyard set ups.

AquaponicsTrying to iron out some of the teething issues is where I come in. As an aquaculture research scientist I research the effect that different diets can have on fish and plant growth – with out aim obviously being to maximise both. Through the development of specialised diets (that not only benefit the fish but also the plants) my students and I have been working to try and find and resolve some aquaponics-related bottlenecks.

The world is changing fast and for me it’s exciting to think that my team’s work will be part of the solution to some of the most serious challenges we face as humans.

The way I see it, we can sit here and wait for someone else to solve these problems – or get our thinking caps on and get involved.

Who knows, you could even get your own little aquaponics system happening at home……


denise briggs Denise Briggs is an academic staff member at the School of Applied Science at the Bay of Plenty Polytechnic in New Zealand. She specialises in marine and environmental research.

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  • Martin Male says:

    Whislt I appreciate the idea of this article, there is a significant problem that this article implies, that there is a shortage of food, there isn’t. Vast amount of edible food is put into landfill as well as being exported from countries where people are hungry/starving to feed the overdeveloped world. Also it doesn’t address the most significant problem facing humans population growth.We simply cannot continue to consume more and increase our numbers.
    The biggest challenge is not food shortage, it is our continued destruction and consumption of the planet we live on. We need to remember this palnet doesn’t need us, we need it;)

    • Hi Martin, thanks for your comment. We agree that the problem is more complex than there being simply a global shortage of food. Something like a third of all food produced is wasted or lost, but the challenge of how to get that food to the people who need it remains. Since much is thrown away or spoiled before it ever has a chance of reaching the world’s poor and hungry, we think the answer is to look in lots of different places for potential solutions. Yes we need to consume less, without doubt, but we also need to help local communities produce their own food so they’re not dependent on aid. We think aquaponics is a really exciting avenue to explore – not just to feed to the world’s hungry, but all of us!

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