SEATTLE — According to the U.N., the world population is more than seven billion, and it is expected to reach more than nine billion by 2050. With a vast majority of the population migrating to urban areas, cities are forced to expand, straining the rural land space and food production. Steven Dring, a co-founder of Growing Underground, believes poor topsoil management and the percentage of freshwater used in industrial agriculture are compounding matters. Dring feels that unless farmers start replenishing the soil’s nutrients, the lifespan of the world’s topsoil is only 80 to 120 years. A solution to these problems is urban underground farming, which utilizes existing underground structures and hydroponics to yield crops using minimal water.

Hydroponics and Urban Underground Farming

Hydroponic technology uses porous material in place of soil and low-energy LEDs instead of natural light. Plants can even sit in nutrient-rich waterbeds where the water is captured and recycled.

LEDs mimic photosynthesis, a process by which plants convert light of certain wavelengths into chemical energy that is stored for future use. The absence of sunlight and the LEDs’ low heat create an ideal growing temperature. Additionally, growing beds are stacked vertically to maximize the space of underground farms.

Underground Farming Around the World

Worldwide, growers are cultivating food beneath the soil. Underground farms are already in England, France and Bolivia, while farms in Sweden and Wales are in development.

England – A World War II air-raid shelter 100 feet below the streets of London was transformed into an underground farm by Growing Underground’s Steven Dring and his business partner Richard Ballard. The farm provides two and a half acres of growing space. Its depth regulates ambient temperature, filters free the air of pests and hydroponics grow the crops. Its business model is more cost-effective than the U.K.’s traditional greenhouse farming; the only consistent expense is the LEDs. Greenhouse farmers use two heat sources: natural light and LEDs (due to short summers). They also use importation to keep a steady supply. Dring believes his company is not replacing traditional farming, just complementing it.

France – In Paris, the startup Cycloponics uses a once abandoned parking garage measuring 37,700-square-feet to grow crops. It is located beneath an affordable housing complex. Cycloponics uses hydroponic farming to harvest microgreens and bricks of composted manure in order to grow mushrooms. The farm produces four and a half pounds of greens each month. In addition, the team harvests chicory — a root which requires no natural light — producing 660 pounds per month.

Sweden – Plantagon CityFarm is building an underground farm in an old newspaper archive underneath an office tower in Stockholm. The company will not only grow food in vertical towers under LEDs, but also heat the building. Instead of capturing the light’s heat and venting it out of the room, it will be sent into a heat storage system to heat offices. CityFarm plans to sell its food locally, which will eliminate shipping costs and pesticide usage and reduce fossil fuel emissions. The company’s innovative approach to urban underground farming is attracting the attention of nations like Singapore and Malaysia, both of which have a shortage of farmable land.

Wales – Abandoned coal mines across Wales are being scouted as new sites for underground farms in the U.K. The country’s coal industry collapsed in the 1980s, leaving mine shafts and tunnels unoccupied; these underground farms could revive them. The project is a cost-effective way of supplying large-scale crops for the growing global population. Advocates say these farms can yield up to 10 times more food than above-ground farms. Coal mine farms would grow plants in nutrient-rich water or suspend them in midair and mist them with water and nutrients. LEDs or fiber-optic technology (both inexpensive methods) would tunnel sunlight deep into the ground, and carbon-capture technology would take advantage of the naturally occurring carbon dioxide. If coal mines are to become underground farms, there will be technical, legal and financial hurdles to overcome before beginning construction. However, this project would generate income and minimize remediation costs. Many hill farmers in Wales are living paycheck to paycheck, and this income would benefit them greatly.

Bolivia – The idea of urban underground farming can be applied to an arid environment like Bolivia’s Andean Plateau. This area contends with frequent drought, frost, high winds and increasing temperatures. Bolivian underground farms are known as ‘Walipinis.’ Only their roofs are visible, for they blend into the plateau’s arid landscape. Internally, bricks absorb the sun’s heat and act as conductors to create warm and humid conditions year-round. They protect crops from the natural elements and ensure food security for farmers’ families. Walipinis have helped farmer and llama breeder Gabriel Condo Apaza improve his family’s diet and save money by no longer purchasing food from markets. Businessman Michael Gemio has refurbished abandoned Walipinis and turned them into an eco-farm. He hires local families to develop the Walipini technology. Walipinis require only a small amount of water to operate, and despite droughts and high temperatures, existing small streams supply this water.

In a Nutshell

Due to rapid urbanization, global cities face problems like unemployment, an inability to meet growing food demands, poor health and pollution, but urban underground farming is their solution. As long as cities implement appropriate policies, underground farms can operate at an optimal level.

– Julianne Russo

Photo: Flickr