Vertical Farming – A User’s Guide
Cities are grounded on mounds of rubbish, where humans live in tiny apartment complexes in towering skyscrapers. Earth has run out of space, and there are just far too many people to feed and house. We are all familiar with the dystopian futures portrayed in sci-fi, and although it’s debatable whether this may eventually represent reality, it still demonstrates how the matter of saving resources is immensely pertinent in our modern world. Scientists are trying to address the limited amount of space we have by suggesting the use of indoor vertical farms.
What are indoor vertical farms?
The definition of an indoor vertical farm rests on a concept developed by Dickson Despommier from Columbia University in 1999. Vertical farms stack upwards, with shelves built in groups inside a tower or limited space. These farms often are environmentally controlled, similar to greenhouses, and involve the use of nonconventional methods to boost growth. Real-world examples of vertical farms are expanding in Singapore and New York, with significant amounts of investment flowing into the industry. For instance, Softbank’s Vision Fund invested $140 million into a vertical farming company named Plenty. While most vertical farms merely focus on mass commercialised production, there are some developers, such as Farmshelf, that produce smaller-scale farms for households or restaurants.
How exactly does a vertical farm operate? The most essential component is usually the use of hydroponic systems to grow the plants. Hydroponics are nutrient-rich solutions that displace the need for soil. Plants are supported in controlled environments where they can grow within small containers, in materials that are porous and readily disposable such as clay or plant husks. This therefore simulates the function of soil, while the use of a solution provides water and nutrients crops need to survive. Other variations of hydroponic solutions have been developed, such as aquaponics (which relies on fish waste to produce nitrates for the plants), or aeroponics (which provides nutrients in the form of a mist).
The structure of indoor farms means that plants cannot just rely on natural light. Instead, most have LED lights that operate for long periods of the day, increasing light intensity during the day and the night. Plants operate on a spectrum, preferring certain wavelengths and specific amounts of light at any given moment. The flexibility of the LED lights allows growers to tailor each individual crop, maximising efficiency and quality of their produce. Farmers also apply these methods with other factors, such as water and carbon dioxide levels. Each of these can be fine-tuned to provide better results with optimal control. This method was first employed in greenhouses, but it is easier to control growth factors within the structure of a vertical farm, since there are fewer external variables, such as soil, to take into account.
Why should we alter our agricultural methods?
There are some immediate benefits to indoor farming. It is immensely time-efficient, as a vertical crop yield only takes around a quarter of the time as one grown in an outdoor field and only half the time as one grown in a greenhouse. While there may be volume constraints in each individual harvest, over the course of a year the advantages become more apparent because there are more frequent harvests. Moreover, the faster cycles of crops ensure that the produce is always in season, thus maximising the quality of the plants. The tightly controlled environments also provide more freshness and optimise the crop for consumption. The produce is healthier since there are fewer herbicides and chemicals applied and the location of the farms reduces the distance of transportation, preventing the produce from going bad or losing its freshness. Given that the average supermarket vegetables and herbs often have lost almost 45% of their flavours and nutrients, this difference is clearly significant. Thus, the small-scale farms used in restaurants have great potential, as their impact is most evident in a culinary scene. The ability for good quality crops to be grown in inhospitable areas such as desert or arctic environments will be very useful for cities that struggle to provide affordable and fresh food due to high import fees and low supplies. The presence of locally grown year-round harvests is likely to lead to cheaper and healthier options.
On an environmental note, the amount of water used is lower than a conventional farm, as the hydroponic system recycles all of the run-off rather than wasting the water. The need for reduced transportation also means a lower risk of environmental pollution happening as a result of shipping produce. Saving city and agricultural space leads to less need for expansion into forests, so the most fertile ground can be used to preserve natural areas.
However, vertical farming has its limitations. In order to access most of the benefits, companies or individuals have to invest vast sums of money. Buying or renting land in cities is expensive, and constructing a specialised building also requires significant investment. Some corporations have manoeuvred around these issues by using old shipping containers to house their plants, but this comes at the trade-off of scale. Louis Albright of Cornell claims that bread made from wheat grown in vertical farms would cost almost $27 due to the high-intensity light and temperature control required. Thus, unless significant technological advancements come, vertical farming is unlikely to be either large-scale or very profitable in the medium term. The prohibitive energy consumption of operating the light intensity and temperature controls also raises issues about sustainability, since most electricity is fossil-fuel derived.
Conclusion: Perhaps not just yet
Overall, vertical farming is an exciting new technology that has immense potential benefits in producing high-quality vegetables and herbs. Due to a lack of readily available technology however, there are justifiable reservations over whether these farms will be ready to displace conventional agriculture just yet. In the short term, they will perform a complementary role to our food supply chain, especially in areas with hostile climates.