I was recently at the National Youth Conference in Canberra on the agricultural work group, our role was to discuss and develop agricultural policy from the preceptive of Australia’s youth. The work group brought together individuals from a range of backgrounds who all a passion for agriculture and wanted to help feed the world into the future. Amongst the many topics that were discussed at the conference one of the ideas that came out of the conference was the concept of the city farm. This is not my idea and its not even a new idea but I believe it is a good one that hasn’t been looked at strongly enough and will have a great potential in feeding the looming world population of nine billion by 2050.
Firstly though I would like to clear up want my definition of a “city farm” is as the definition of what a city farm is was something that we had some trouble with. By my definition a city farm is commercial scale operation in an urban area that produces food hydroponics and aquaculture or a combination of the two. This differs from other definition that many other assumed, that definition being a network of community and roof top gardens. While I have no problem with these smaller community projects they are not a realistic method of feeding the world’s rapidly rising population.
The need for new and innovate ways to produce more food for the world using less land and inputs is becoming more apparent as issues like climate variability, mining and urban encroachment take their toll. We will need to produce more food with less land and less water in order feed the world, I also believe that we will need to be closer to our markets in the future as fuel prices continue to rise making cost effective transport more difficult. In order to achieve this I believe that we will need city farms that can produce large scale commercial crops.
Closed hydroponics have been shown to recycle over 95% of the water in the system (Practical Hydroponics and Greenhouses) as there is no evaporation and no leaching so the only water that is lost is the water used by the plants. It also uses 30-40% less fertiliser than regular cropping (Woolworths Article) as the nutrients are in a contained system and like the water only nutrients used by the plants are removed from the system. These systems would be much efficient in terms of water and nutrients allowing much more food to be produced from the same inputs.
I believe that aquaculture also has a role to play in the future of city farming as fish can be grown indoors in large tanks. While there is currently some concern about the sustainability of fish farming due the fish-meal comprising of mainly wild caught fish I believe that they could be fed on grubs and larvae that are cultured in waste products. The two systems may even be linked together into a system called “aquaponics”
Aquaponics is a combination of aquaculture and hydroponics where the waste water from the fish tanks is filtered though the hydroponic system allowing the plants to feed on the waste from the fish. This closed system again works to save water and nutrients through limiting loss to the outside environment so all that is lost is what the plants and fish use.
I understand that in order to build and run one of these city farms the costs will be huge and there will be a massive need for labour. But there is already commercial aquaculture and hydroponic farms so I know its possible and while I am unaware of any in Australia there is already farms overseas using aquaponic technology.
Will it be for me?
Probably not, I much prefer the open spaces of the country to the crowded concrete jungle and view from the tractor cab to the bumper to bumper grid lock. I believe that there will still be a place for conventional farming in the future but I also believe this is something that has the potential to feed the worlds ever growing population.
To read an article in “The Land” on city farms click here
And to read about the worlds largest vertical farm click here