In the last post, which you can read here, I introduced you to the state of the world, specifically, the impact that agricultural activity has had, and continues to have on the environment around us. At the end, I mentioned how vertical farms and their related technologies could serve as a saving grace for us. So what is vertical farming?
From horizontal to vertical
The traditional farming model is one with which so many of us are familiar – flat, far-reaching fields, plowed, sown, irrigated and grown – then, a few months down the line, provided no major calamity has occurred, the produce is harvested.
As of April this year it was estimated that the global human population had reached 7.5 billion and that largely owes its success to the availability of food, an availability which exists due to our agricultural technologies. However as the global population continues to grow, those technologies have to change too, because we are running out of viable farming space as well.
As mentioned in the last post, those farming technologies aren’t without their side-effects, an array of symptoms which include increased CO2 and Methane production, deforestation, wasteful water consumption, polluted water runoff, soil degradation, and ecosystem destruction.
When faced with an inability to spread out, a natural conclusion is to go up. Thus enter the concept of farming vertically.
Vertical Farming: The Basics
So with the need to grow produce upward instead of outward, how does one do that? Well, there are three main ways in which I have seen this happen.
The first method is to grow the plants in vertical pipes, with holes or sockets in the sides where plants can be slotted. Nutrient filled water is sprayed or dripped down the centre of the pipes which the plants absorb on its way down, and remaining water can be collected at the bottom again. For the space that each of these pipes occupies, each has approximately 30 plants growing in it – far more productive than if a plant was grown in the ground. Because the plants are watered from inside the pipe as well, the system is also far more water efficient compared to traditional growth as well.
The second method is that the plants are grown on revolving A frames, rotating the plant beds to maximise even sunlight distribution and water distribution. Tall and narrow, this growing method also efficiently makes use of limited horizontal space in favour of vertical space.
In this instance, each tower is six meters high and have between 22 and 26 growing troughs, which provides a lot of growing space. To top it off, the rotating mechanism is a self-contained water loop, making these efficient to run as well.
The final method is stacked growing beds, with LEDs that not only make up for what would otherwise be inconsistent light sources but also often finely tuned into a custom light ‘recipe’ to maximise plant growth. Like the other two methods, this one is also efficient in space usage, and whilst more costly to power, it can grow plants quickly if the tailored lighting is used.
With these three methods in mind, if we think back to the issues of traditional agriculture, we’re already starting to solve some of them. All three of these systems have a vastly more efficient water usage, and no polluted runoff if built to capture and recycle the water used. They aren’t eroding or degrading the soil and they are producing more produce compared to a horizontal arrangement. Both the pipes and A frames have the ability to be grown indoors or outside, while the stacked beds are an indoor approach. If grown outside there it is more than likely that herbicides and pesticides will still be used, however indoors there would be a reduction I chemical usage. While this leaves many issues unresolved, vertical farming has the ability to be taken to the next level.
Vertical Farms: Going Up!
The conversion of a farmyard barn or inner city warehouse into a building that houses a production system like any of the three methods above is an achievement. For a relatively low infrastructure cost, a high yield rate is achieved relative to the space used. While there are many improvements to be had and limitations to contend with, the biggest limitation is still ironically, space. If the farmer wanted to start making the system more efficient and produce an additional product, he can add fish tanks and turn his production into an aquaponics system. The problem is fish tanks take up space, if you have them inside, they compete with the plant arrays. If you have the option to put them outside, they may then be in the way of something else. If the farmer simply wants to increase his production, he is limited by the height of his building. Thus once again, the solution is to go up.
By going up, additional space is created, that not only allows for more production, an increase in the range of products, but also more complimentary produce that have byproducts which help to grow other produce. A well designed vertical farm should be self-sustaining, with minimal or non-existent waste, and a range of products that includes not only food but also fuel, electricity, packaging and compost. This ideal vertical farm ‘anatomy’ includes a wide range of plant and animal cultivation, including aquaculture, aquaponics, hydroponics, aeroponics, algae and insect farming. These buildings could meet their energy and water requirements through rain collection and water recycling, solar and wind generation, and electricity generation either from biogas or biofuels. The lowests floors could hold supermarkets, restaurants or packagings plants filled with the produce grown in the floors above and packaged in biodegradable packaging produced on site. Tune in next time as we continue to explore the vast possibilities vertical farming provides.
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