Vertical farming is a soilless method of growing produce indoors in which plants are cultivated in stacked layers in a precisely controlled, laboratory-like environment. All the factors that affect a plant’s growing conditions are controlled to a precise degree: light frequency and intensity, temperature, humidity, nutrients and water levels. Planting containers are stacked on shelves or hung on layered fences to maximize available square footage while produce is treated to perfect growing conditions 24 hours a day.
Because of the tweakable environment vertical farms offer, non-native crops can be grown in areas where they are typically shipped in from thousands of miles away. Vertical farms from Singapore to the United Arab Emirates have been able to reduce water consumption, carbon footprint and food waste, all while eliminating the use of pesticides and growing produce like strawberries and kale that would otherwise be shipped in from colder countries.
How the vertical farming works
Vertical farms use hydroponic or aeroponic techniques to grow produce; roots hang down into a nutrient-rich water source (hydroponic) or are periodically misted with nutrient-rich water (aeroponic) while hanging in an enclosed chamber. Rather than draining into the soil, the nutrient-enriched water is collected and recirculated in a “closed loop” system, eliminating water waste and nutrient/fertilizer runoff.
AeroFarms, based in New Jersey, says its vertical farm system uses up to 95% less water than a conventional farm. Plenty, a vertical farm company based in San Francisco, makes a similar claim that its farm uses just 5% of the water and less than 1% of the land compared to outdoor farms.
LED lights provide fine-tuned levels of color spectrum and intensity, which increases growing speed and influences physical characteristics like texture, flavor and color. Temperature and humidity controls allow for hardy crops to grow without being subjected to sun degradation, heat swings, heavy storms or droughts — all while improving the crop’s flavor, appearance and shelf life.
Because vertical farms are indoors, most are able to operate using integrated pest management practices instead of pesticides. This makes it easy for vertical farms to produce a certified organic crop, which raises the demand and value of the produce.
Automation enhances productivity and promotes social distancing
Using sensors, machine learning and artificial intelligence, vertical farm operators are able to fine-tune the exact parameters needed to grow each crop variety to maximum yield and peak flavor. Data management technology allows vertical farmers to analyze and optimize each part of the growing process for maximum yield, quality and efficiency.
Additionally, the ability to monitor and adjust environmental factors remotely or automatically through artificial intelligence cuts down on the manpower needed to maintain a farm, saving on labor and healthcare costs.
With less workers in a facility, social distancing measures can be more easily upheld. Crops grown in vertical farms also come in contact with fewer people during the growing cycle and while being packed and shipped.
Unfortunately, vegetables are commonly recalled for salmonella, E. coli and listeria contamination after being exposed to animal waste or an improperly cleaned processing facility. Vertical farms eliminate this risk due to the nature of their clean, controlled environment.
Vertical farming as a sustainable update to the supply chain
Singapore, the densely populated Southeast Asian economic powerhouse, doesn't have much farmland on its 714 square miles, and as a result, 92% of its vegetables are imported. But Sustenir, a vertical farming company based on the island has stepped in to supply leafy greens and cold-weather produce like kale and strawberries.
Instead of having them imported from thousands of miles away, they’re growing them in the same neighborhoods as the markets selling them. Sustenir even guarantees its produce for up to two weeks in the consumer’s refrigerator — which it’s able to uphold because the product spends so little time between being harvested and stocked in a market.
Research shows that light, heat, storage time and handling can reduce the amount of nutrients in vegetables. In vertical farms, crops can be picked and shipped on the same day to markets or transferred fresh to on-site cold storage.
Compared to picking crops from a field and shipping them thousands of miles across a highway or ocean exposed to the elements, vertical farming greatly reduces food waste, labor requirements and shipping-related carbon emissions, while improving the quality of the end product.
The current supply chain uses mega-producers that can’t quickly respond to changes in demand — which we saw when COVID-19 outbreaks led to labor shortages and panic-buying, leaving empty grocery store shelves and leading to purchase limits on staple items due to supply shortages.
If producers locate vertical farms in urban areas based on the markets they serve, they could drastically reduce transit time and shipping costs while retaining the ability to make real-time adjustments to the products they grow in accordance with sales and supply chain fluctuations.
Vertical farming’s potential improvements to food security
- Weather events like droughts and torrential rain don’t pose a threat to vertical farming facilities, while conventional farms can have an entire harvest ruined by an adverse weather event or unfavorable growing season conditions.
- Drastically reduced shipping distance cuts down on food waste and degradation that takes place before produce hits the shelves.
- Most vertical farms aren’t affected by supply chain interruptions like COVID-19 due to their close proximity to the markets they serve.
- Networks of vertical farms that serve individual, hyperlocal areas can replace mega-producers that ship nationwide.
- The ability to grow many different varieties of crops in vertical farms allows farmers to grow and supply produce that would be out of season using conventional methods.
- Frees up local farmers to grow crops that are well-suited to their area with conventional methods, instead of struggling to grow non-native crops that require more water, fertilizer or pesticides.
Downsides to vertical farming methods
- High entry costs: Between purchasing/renting warehouse space and vertical farming equipment, the initial investment could be in the millions, depending on the size of the facility.
- Energy intensive: Powering the LED lighting and HVAC systems needed to create the perfect growing environment uses significant energy and will constitute a large portion of ongoing costs.
- Not quite carbon neutral: Though vertical farming drastically reduces the carbon footprint associated with shipping and packaging foods across the globe, the power needed to operate the indoor facilities is still substantial.
- Backup power required: Backup power infrastructure is required to protect the facility’s harvest in the event of a power outage to continue feeding plants, maintaining climate conditions and powering lighting.
The future of vertical farming
Vertical farming still has hurdles to overcome before becoming a major part of the supply chain. Power consumption, high investment cost, advanced technology requirements and market demand are all factors that could make or break your decision to venture into vertical farming.
While there is still work to be done to make vertical farming a truly sustainable method of food production, there is much potential for it to revolutionize every part of the journey from seed to shelf.
Todd Allsup is divisional vice president of corporate sales, and Kurt Warzynski is vice president of process engineering at Stellar. Stellar is a fully integrated design, engineering, construction and mechanical services firm based in Jacksonville, Florida. Visit the company's blog at www.stellarfoodforthought.net or learn about its projects at stellar.net.
