Is It Locally Produced? Yes, Directly From The 5th Avenue!

Why skyfarming may be key to feed an ever growing world population

Photo credit: Oasis Biotech

For those of you who has long planned on quitting a boring office job and starting a farm, to finally enjoy life in contact with nature…I have bad news: while the farmer of the future will still spend time among vegetables, “the farm” will likely relocate from a hilly and green countryside to the top floor of a skyscraper, maybe even in the city center! Does it sound good anyway? If so, I then encourage you to give it a try!

Why growing salad on the 10th floor?

As odd as it may appear, skyfarming (aka, growing crops on vertically staked layers) will probably become the new way of producing food for an ever growing world population, which is expected to hit 9 billion pepople by 2050. At present, 80% of suitable land for agriculture has already been used. Assuming (unfortunately it is a wrong assumption though) we do not want to expand agricultural land into natural forest areas, the only way the production rate can cope with the speed at which the global population is growing, is the optimization of the cropping systems. Otherwise, as we built skyscrapers to optimize the use of land for housing purposes, we could “farm vertically”, instead of horizontally.

Vertical farming took off in Singapore 8 years ago, triggered by the impossibility of feeding a population of (back then) 5 million people with only 250 acres of farming land. SkyGreen, the company set up to meet this challenge, is nowadays capable of providing a yearly production of 500 tons of leafy greens, growing on a series of tiered towers, rotated by a water-pulley system.

Ok, but how does it work?

Although vertical farming is a practice which probably would not appear as good as traditional farming on Van Gogh’s canvas, it is undoubtedly much more environmentally friendly. The technology itself consists in growing crops (mainly leafy greens) in a controlled environment, using soilless farming techniques such as hydroponics, aeroponics and acquaponics.

Hydroponics

The most common soilless technique on vertical farms is hydroponics, which uses a solution of water and nutrients to support crop growth, granting a water saving of about 90% as compared to “soil-based” farming. In addition, in some vertical farms like SkyGreens, the water used for both growing the crops and moving the rotating towers which allows the plants to have a uniform light distribution throughout the day, is collected rainwater. In compliance with sanitary regulations, it is even possible to use wastewater in a hydroponic system.

Aeroponics

Aeroponics takes vertical farming to the next stage. For someone like me who has problems growing plants in a pot, this technique is mindblowing: the plants are simply left hanging from a support (usually a layer of foam) with the root system in the air, periodically puffed by misting devices, which dispense both water and nutrients. What is not taken up by the plant is recycled, allowing for a 95% of water saving, as compared to regular farming. Another advantage of this system is the higher growth rate of the plants (about 30% faster than conventional farming).

Acquaponics

Acquaponics is a technique which combines agriculture and acquaculture. In these systems, crop growth is based on the use of water coming from fish farming: the incoming water is rich in nutrients due to the high level of inputs (feed and animals’ droppings). The plants take up these nutrients purifying at the same time the water, which can be then relocated to the fish farms. This technique allows for an even higher plants’ growth rate than in normal hydroponics. Water saving/recyclying and a lower use of fertilizers make acquaponics particularly sustainable, from both an economical and an environmental point of view.

Why can vertical farming be a winning strategy?

At this point, since vertical farms are located in the city, you may expect that the veggies might get contaminated by that air pollution which drives us to the countryside over the weekends, to get a breath of fresh air. Well, luckily for us, vertical farms are set up as a controlled environment, where the incoming air is filtered and purified, preventing therefore the contamination by external pollutants. Besides allowing for a much lower use of space to grow food, vertical farming has also other advantages:

  • The control of pests and diseases is also much easier compared to traditional farming, allowing for a lower use of pesticides
  • The use of herbicides is virtually non-existent, given that we are in a soilless system
  • Vertical farms can produce food which we could find in the supermakets virtually located 500 meters from the “farm”, considerably reducing the environmental impact caused by transportation

However…

Of course, vertical farming requires a certain level of technology to function. The plants must be grown at specific environmental conditions (i.e. humidity, temperature, light), to avoid crop failure and the spreading of diseases. Especially in aeroponics temperature ad humidity are two key factor to pay attention to, since the plants have the roots in the air and are therefore more prone to drying out. Hence, a simple mulfunctioning of the system might lead to a significant crop loss.

Energy-wise, vertical farming uses a lot of electrical power which needs to be working 24/7. This makes vertical farming very expensive and might cause sustainability problems which risk to overall outweigh the advantages of the system. Nevertheless, modern systems are based on the use of photovoltaic systems, which can both supply the required energy and reduce the environmental impact.

Despite these challenges, according to a report by market intelligence firm IDTechEx, vertical farming is expected to rise from USD $ 781 million in 2020 to USD $1.5 billion by 2030.

Although vertical farming is not a silver bullet to tackle the problem of food production for a fast-growing population, it can anyway be part of the solution. But what about you? Would you eat food grown in vertical farms?

Agronomist and traveller. Passionate about sustainability and philosophy. Admin of blog https://agrisustainia.wordpress.com/

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