Vertical farming is a frequently discussed topic when considering the future challenges of feeding the world, combating climate change, and promoting sustainable agriculture. While the impressive image of enormous modern vertical farming buildings tends to capture the most attention, there is another version of vertical farming that is often overlooked despite its many benefits: underground farming.
Underground farming (as the name suggests) is a type of vertical farming that takes place beneath the earth's surface. One highly successful example of an underground farm is "Growing Underground", located in Clapham, London. Founded by Richard Ballard and Steven Dring in 2012, both of whom had prior experience in the food and drink industry, the idea for this unique farm was sparked by a discussion about using abandoned underground spaces in London to grow crops. Initially, the company focused on research and worked on a project together with the University of West London. However, soon after it transitioned into a commercial venture. In 2015, Growing Underground launched its first yield of microgreens, marking a significant milestone in its journey from concept to reality.
What are microgreens?
Microgreens are young seedlings of vegetables or herbs that are harvested shortly after their first leaves have developed. They are commonly used as a garnish on dishes, in sandwiches, or as an ingredient in salads. Growing Underground specializes in cultivating microgreens with a focus on varieties such as mustard, fennel, and radish. The farm produces an impressive 2,500 kg of microgreens annually, which are sold to a diverse range of customers including restaurants, retailers, and consumers through its online store.
What abandon underground space has Growing Underground been using to operate their vertical farm? Growing Underground's vertical farm is located in a World War II air raid shelter. What a fascinating use of an abandoned underground space. This means plants are growing an astonishing 33m underground on an area of about 550 m2. Growing Underground utilizes hydroponic farming technology to grow its crops. The hydroponic system uses a nutrient-rich water solution instead of soil to nourish the plants. The system recirculates the water to minimize waste and reduce the farm's water consumption. To maintain optimal growing conditions, the farm uses a computer-controlled climate system, including natural ventilation, fans, cooling units, and LED lamps for lighting.
One of the most cost intensive aspect of a vertical farm is its lights. Energy consumption is reduced by using energy-efficient technology, and the farm is powered by green energy sources such as wind and solar power. The underground environment provides a constant temperature ideal for plant growth, but the farm still carefully manages humidity and temperature through its advanced system.
Have you ever wondered why vertical farms focus mainly on growing leafy greens, herbs, and microgreens, rather than fruit and vegetables (like strawberry) that can earn farmers much more income? There are a few reasons for this. Firstly, leafy greens have a shorter growth cycle than most fruits and vegetables. This means that vertical farms can produce multiple harvests of leafy greens in the same time it takes to grow a single crop of fruit or vegetable. Additionally, indoor-grown plants are more vulnerable to pests and diseases, and strawberries are especially susceptible to a long list of pathogens, making them a difficult crop to grow indoors. Leafy greens also require less space and fewer inputs, such as water and fertilizer, making them more cost-effective for vertical farming. While strawberries and other fruit and vegetable crops may be grown in vertical farms, they present unique challenges that require more space, resources, and expertise to overcome. This is why leafy greens remain a popular and practical choice for vertical farm owners.
Does this mean that all vertical farms exclusively grow leafy greens? While many vertical farms focus on leafy greens, there are some that have been successfully growing fruit crops such as strawberries. One such example is Oishii, a US-based vertical farm that specializes in high-quality strawberries, producing about 150,000 kg of the fruit per year. Oishii is definitley an exceptional farm. Growing strawberries in a vertical farm is very expensive, which is why many strawberry vertical farms have gone bankrupt in the past decade. Oishii is able to stay afloat by selling their fruit at a premium price. A small box of Oishii strawberries containing six to eight berries can sell for around $50 USD or more in certain markets.
Let’s come back to underground vertical farming. Using empty unused spaces in big cities might be the only possibility to bring vertical farms inside busy and densely populated cities. The vertical farming company Cycloponics Farm started in an old underground car park in the middle of Paris, France. Founded in 2016 by Antoine Hubert, a biologist, and Thibault Masson, an agricultural engineer, the company specializes in mushrooms, endives, and microgreens.
Mushrooms growing in Cycloponics Farm. Images: Cylcoponics Farm
The idea of this innovative approach to farming sparked when both founders were working together on a project that aimed to create an aquaponic system that would allow people to grow fish and vegetables together in their own homes. After conducting extensive research and testing different farming techniques, the founders launched Cycloponics Farm in 2016. They opted for a circular design for the farm to maximize space and minimize energy consumption. Additionally, the farm's underground location helps to regulate temperature and humidity levels. They are able to grow pesticide-free, thus their produce is in high demand by local restaurants and markets. The founders' innovative approach to farming has also attracted media attention and investors. As a result, they have received funding from various sources.
Using empty, unused spaces in big cities such as underground car parks or war shelters is a creative solution to bring vertical farms closer to urban consumers. Cycloponics Farm and Growing Ungerground are excellent examples of how we can use such spaces to improve the efficiency of food production in urban areas while offering fresh, healthy, and locally grown produce to city dwellers. While this definitely helps tackling one challenge of modern crop farming of the near future, the biggest challenges of vertical farming remain optimizing plant growth in an indoor (vertical) system, especially of fruit and vegetable bearing crops, and reducing energy consumption of LED lamps.