Making sense of the terms in Vertical Farming

By Meghan Horvath, EUFIC

What exactly is vertical farming? I know that I picture stacked layers of plants sprouting in organised rows inside some big, bright warehouse.

Putting it all together

This isn’t quite wrong. Columbia emeritus professor Dickson Despommier is credited for making the term mainstream. His definition refers to a method of growing crops, “usually without soil or light, in beds stacked vertically inside a controlled-environment building.”¹

Definitions certainly vary. The Vertical Farming Institute in Vienna defines VF as “agricultural production inside buildings, in the metropolitan areas of cities,” therefore often repurposing existing structures for use as vertical farming facilities.²

VF is primarily used for food production, but not exclusively as the process can be applied for horticulture purposes as well. Regardless, when reading about vertical farming, there are several terms that are often used interchangeably, making it hard to understand just what they describe. For clarity, we put into context the following key terms when discussing the topic of vertical farming.

An overview

• Controlled Environment Agriculture (CEA)
  • Vertical Farming
    • Hydroponics
    • Aquaponics
    • Aeroponics
  • Rooftop Farms
• Indoor Plant Cultivation, Indoor Farming
• Urban Agriculture, Microgreens

Why not familiarise yourself with the language, —we’ll also link terms within future blog posts back to this page to guide your reading and help when in need of a refresher.

Controlled Environment Agriculture (CEA)

CEA is an umbrella term for the many ways of growing crops indoors.³ An easy way to look at it in the context of VF, is that VF can use CEA technology. CEA includes greenhouse agriculture, vertical farms and some rooftop farms.⁴ Plants are grown in a controlled environment using technology to ensure crops are growing under optimal conditions, which, in the most advanced forms is without the use of soil.

It is important to note the debate around energy consumption and the CO2 footprint of current CEA systems. Critics argue CEA is expensive and requires a high use of energy as artificial light must be created.⁵ However, this system also uses less water than traditional methods and allows year-round crop production and thus often higher crop yields.³

Vertical Farming (VF)

VF is a type of CEA and is considered a system of food production where crops are cultivated on vertically stacked levels in buildings.⁸

Predominantly, VF takes place without soil and natural sunlight. These resources are instead provided via the use of artificial lights and growth systems that give the crops the nutrients they need.⁹ 

In some cases one acre of vertical farming can provide the produce equivalent to between 10-20 acres of conventional agriculture.⁹ With climate change expected to pose a major issue for crop production due to increasing temperatures, carbon dioxide emissions and severe weather events, vertical farming presents an alternative to existing farming methods that aims to address these issues.¹⁰ 

Critics of VF, however, see even greater increases in pollution and greenhouse gas emissions and argue against how expensive the technology is.¹⁰ From a climate standpoint, some argue that going vertical, sustainably, would require advances in renewable energy because of today’s high carbon cost due to light for vertically farmed crops.⁸

There are three growth systems you can use inside a Vertical Farm:

• The first type of CEA is Hydroponics, a water-based growth system without soil in which a nutrient solution is pumped around reservoirs that plant roots grow directly into.⁶  ​​​​This system is also widely used in greenhouses.  
• Next is Aquaponics, which is a combination of hydroponics and aquaculture, so plants grow in an aquatic environment with nutrients that come from aquatic species raised in tanks, i.e. fish.⁷
• Next is Aeroponics, where plant roots grow not in a base of soil or water, but where a water and nutrient solution is sprayed directly onto them.⁵ The unabsorbed mist then condenses and returns to reservoir tanks to be used again, preventing the plants from becoming water-logged.³

Rooftop farms

The next type of CEA, rooftop farms are found to regulate building temperatures in New York City while using 75% less water than conventional farms.⁴ Within rooftop farms and VF as well, all production factors can be regulated as crops grow in a closed system.

This allows for a more self-sufficient, circular economy in which crops can grow faster and year-round, producing greater yields without harming more land by overuse and use of pesticides.¹⁰

Indoor Plant Cultivation

Indoor plant cultivation is a way to describe how CEA can allow for optimal growing conditions. This method arguably promotes food security by avoiding uncertainties in terms of climate and environmental factors, while making it possible to grow certain plants anywhere, even in cities.⁶

Indoor Farming

As Dickson Despommier, the Vertical Farming spokesman once said, “Nature will repair itself if you give it a chance, and indoor farming gives it that chance.” While land loss, overuse of pesticides and soil degradation is a serious, global issue, what is often overlooked in the discussions on VF is the very specific local, country and city contexts. Not all areas around the world have the same pressing issue of pesticide over-application, soil degradation and loss of agricultural land.

Urban Agriculture

Still, as the world’s population increases, and people increasingly move to cities, our food system and conventional food production is feeling the pressure.¹³ Urban Agriculture or “the growing, processing, and distribution of food and other products through plant cultivation in and around cities for feeding local populations” is thus becoming a more viable option.⁴  Urban Ag can provide fresh food where people live, cutting down on food miles and often creating a true community of self-sufficient urban growers in the process. Urban Ag also may use less land, less water, and have less production loss to pests and diseases, while allowing for year-round crop production, as well as increased daylight hours or growing time per day.⁹

Critics point to the cost of this method and find it hard to alleviate food deserts when producing food in this way is so expensive. Are we not just making hipster food for yuppies? What should be kept in mind as well is that even if urban populations are rising, at present and in the future many people will still live in rural areas – a factor often overlooked in discussions on sustainable, local food production. It’s important to note as well that there are a lot of crops that simply cannot be grown indoors, at least not yet.

Microgreens

Microgreens, lettuce and herbs, for instance, consist of the bulk of crops produced indoors with this technology.¹² However, in a few years and with technology progression, other crops such as cucumbers or tomatoes could be grown at an affordable price. Therefore, indoor farming is not necessarily the solution to solving hunger in the face of a changing climate, but it may be a part of it.¹¹

What do you think about these technologies? Will they become the norm? Let us know your thoughts in the comments below! Also watch for our next blog and series as part of our Cultivating Engagement project, where we’ll expand on how horticulture and agriculture fit into the conversation.

References

1. Frazier I (2017). The Vertical Farm. The New Yorker.
2. Vertical Farm Institute. What Is Vertical Farming?   
3. FreshBox Farms (2016). Controlled Environment Agriculture (CEA): More than Hydroponics. Medium.
4. Game I, Primus R (2015). Urban Agriculture. Sustainable Development UN.
5. Balch O (2018). This Swedish Indoor Urban Farm Wants To Revolutionize How We Live And Eat. Huffington Post.
6. Cornell University College of Agriculture and Life Sciences (2012). About CEA.
7. European Commission. Aquaculture.
8. Schubert D, Vrakking V, Zeidler C (2013). Feasibility Study: Vertical Farm EDEN. ResearchGate.
9. Welsh Government (2018). Vertical Farming: A new future for food production? Business Wales.
10. Coyle B, Ellison B (2017). Will Consumers Find Vertically Farmed Produce “Out of Reach”? Choices Magazine. Agricultural & Applied Economics Association.
11. Caughill P (2018). Urban Farming Is the Future of Agriculture. Futurism.
12. Haspel T (2016). Will indoor, vertical farming help us feed the planet – or hurt it? The Washington Post.
13. FAO. Urban agriculture.