I saw an interesting story on the news, the other night, about high-quality farmland being turned into a solar-energy farm. Now, renewables are great, of course, but the point is that there was plenty of less-valuable land that could have been used for solar production, instead of this good agricultural land.
This story highlights an increasing problem – loss of food-producing land to things like urban sprawl and power generation. Obviously, people need places to live, and most of us like to be able flick a switch and have the lights come on. But in a lot of cases, land that is needed for growing food is being used for these purposes instead.
As populations increase, so does the demand for food, housing and power. It can be a tough call for councils to decide which one to do with a piece of land. Personally, I would like to see rich farmland remain as farmland. But in many cases – certainly a lot of the time in my general region – it gets put under houses. What a waste! Houses could easily be built on less-fertile soil, but councils don’t seem to pay much attention to that idea. It’s a bit short-sighted, really. Our good farmland keeps getting buried under housing estates, and our farms get left with the less-productive areas. What a dumb thing to do.
Another thing that is decreasing the amount of farmland available to us is soil depletion. After years and years – sometimes generations – of farming in the same place, the ground just can’t support crops any more. No matter how much fertilizer is added, things just don’t grow very well. Often in cases like this, the land just gets abandoned. Sometimes it recovers, sometimes it doesn’t. It can take years, if it does recover, during which time it’s not useful for food production.
But in amongst all these problems is a great solution – aquaponics! Since the food is not grown directly in the ground, the type of land doesn’t really matter. Poor soil? Not a problem. Depleted land? Not an issue. I have seen aquaponics farms successfully run on old industrial sites. In fact, one of my past MasterClass students has set up a hugely productive aquaponics farm on reclaimed land in Hong Kong. This is an excellent use of waste land. It also has the advantage of putting food production close to the population that consumes it. I strongly believe that, in future, this is going to become more of an issue – especially if international trading partners start cutting each other off!
Another advantage of aquaponics is that it is a high-density production method. Because each plant has a constant supply of abundant nutrients, they don’t need to compete with each other like they do in a traditional farm or garden. This means you can grow a lot more food in the same amount of space. With populations increasing so dramatically, it is going to become increasingly important to get as much out of our food production as possible, and aquaponics is well suited to fit this need.
Being such productive systems, aquaponics farms don’t have to be very large, either, to provide ample food to the local area. That farm in Hong Kong that I mentioned earlier has only about 2000 square metres (about half an acre) of growing space. You could easily build an aquaponics farm that size within the city limits. Every now and then you’ll hear about some community group that has taken over an old rail yard, for example, and turned it into a community farm – using traditional growing methods, usually, but the point is that there is space in most cities for things like this. You could even build an aquaponics farm on a series of rooftops, if you wanted to.
Water retention within an aquaponics farm is another reason they can be built just about anywhere. The same water constantly circulates in the system, so there is no regular outlet of water into the environment. Only in rare cases do you need to release any of the water from an aquaponics system, so you don’t need access to large-scale water outlets or water-treatment plants. This makes finding a farm location a lot easier.
Obviously, what you are building on will influence how you build your system – can you bury your pipework, can you put your sumps into the ground, that sort of thing. But these are secondary issues and easily resolved with a bit of creative thinking. One of the farms I’ve seen in Asia is built on concrete, so no chance of burying the pipework or sumps. It’s all above ground and works just fine. But it just goes to show the versatility of aquaponics, that you can grow a huge amount of rich, healthy food on solid concrete! How good is that!