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Sustainable vertical farming offers food for thought in a changing world

An experimental plant factory with artificial lighting is seen at the Japan Plant Factory Association facility on the Chiba University campus in Kashiwa, Chiba Prefecture, in this undated photo provided by the association.

There is a vegetable farm, but not just any farm; it is a vertical farm. There is no tractor. There is no farmer in dusty overalls, no barn cat or even a barn. There is no sky, no field; only a warehouse with rack upon towering rack, each level boasting a bounty of growing vegetables lit by banks of LEDs. And it could prove a vital component in the future of sustainable food and food security on our warming world.

    Perhaps you're not so keen on vegetables grown in a place like a garden center crossed with "Tron." So let's clarify one thing: vertical farms are not organic. A more minutely human-engineered, human-controlled environment would be hard to imagine.

    But control is the point. Vertical farming startups claim they can grow hundreds of times more produce -- usually leafy greens -- per unit area than a traditional open-field farm, while cutting water use by 95% or more. And they can maintain production year-round, with no worries about crop-destroying pests and thus no pesticides, while the plants get exactly the water and nutrients they need.

    Driving all this is a level of automation that separates the farms, also called plant factories, from typical greenhouses -- and gives the cutting-edge agriculture startups a cultural flavor more California tech than rural farmhouse. One firm, Bowery Farming, even calls the software running its farms in New Jersey and Maryland an operating system.

    "BoweryOS," the company told The Mainichi in an email, sucks up "millions of data points through proprietary machine learning algorithms along with an extensive network of sensors and cameras," 24 hours a day, seven days a week. The system, Bowery states, allows constant tweaks and improvements to the entire cultivation and harvesting cycle, "cutting down on waste throughout the entire process."

    For any sufficiently sophisticated vertical farm, all this applied technology means that the use efficiency of "light energy, water, fertilizer and land area are already much higher than those of open fields and greenhouses," says Toyoki Kozai, professor emeritus at Japan's Chiba University and honorary president of Japan Plant Factory Association. For example, "water used for irrigation per kilogram of produce in plant factories with artificial lighting (PFALs) is 5-10% of that in open fields, because 95% of transpired water is condensed and collected to be recycled" in the vertical farm's cooling system.

    Plant factory experimental facilities and greenhouses are seen on the Kashiwa campus of Chiba University in this photo provided by the Japan Plant Factory Association.

    For someone living in a place where fresh water seems abundant, this focus on water may sound over-the-top. However, a 2017 United Nations Food and Agriculture (FAO) report notes that, on average, 70% of global fresh water use already goes to crop irrigation. Meanwhile, worldwide food production overall has doubled in the last 30 years, but an estimated 60% more will be needed to feed all 9.7 billion people the U.N. projects will be around in 2050, 68% of them in cities. That translates into water needs ballooning another 50%, though the FAO says we can only afford to squeeze another 10% from the environment for agriculture.

    Furthermore, even before expanding it to meet growing food needs, conventional agriculture is already contributing heavily to the greenhouse gas emissions driving climate change. A 2019 FAO report states that "the world's cultivated soils have lost between 50 to 70% of their original carbon stock, which has been released into the atmosphere in the form of CO2 ... contributing to global threats such as climate change, and costing trillions of dollars per year."

    In this context, it seems almost miraculous that a farm could use so little water, little or no soil, and be built just about anywhere, drastically shortening supply chains and the CO2 emissions that come from shifting produce over long distances. But vertical farming is no agricultural cure-all.

    Joel Cuello, a professor of agricultural and biosystems engineering at the University of Arizona, told The Mainichi in an email interview that while vertical farming "is not a panacea for addressing the challenge of meeting the world's prodigiously growing food demand," it is a "vital and competent" part of what Cuello calls a "portfolio" of innovations.

    Raymond Wheeler, a plant physiologist at NASA's Kennedy Space Center working on technology to grow food crops in space, said of the promises of vast energy, water, and other resource savings touted by some vertical farming startups, "I think some claims are credible, others are a bit of a stretch." For one, some water recirculation technology employed in vertical systems is already used in conventional hydroponics, so the astounding efficiency figures depend on what the systems are being compared to.

    Touching on the industry's relative infancy, Wheeler said, "I think maintaining sustainable operations is also a challenge. Can your system produce as well after 10 years of operation as it did in year one?" Nevertheless, the NASA researcher believes "vertical farming is very volume efficient especially if you have land area constraints, such as in urban settings."

    However, it is unlikely to meet all our plant-based food needs. Professor Cuello notes that "in general, commodity crops (e.g., rice, wheat, barley, corn, etc.) which are typically grown on a large-scale and sold in bulk at low prices are not appropriate" for vertical farming. Chiba University's professor Kozai echoed that view, noting that staple crops "require high light intensity and a long cultivation period, and the weight ratio of salable parts (grains) to the whole plants is very low."

    Mike Dixon, a professor at Canada's University of Guelph who also cooperates on NASA research into agriculture for space, agreed. However, he also said that the technology needs to move beyond growing leafy greens, which will "only get us so far."

    "We need to get our head out of the lettuce box," said Dixon. "Lettuce is not food." He advocated for moving vertical farming into higher nutrition crops like legumes.

    Another potential stumbling block is energy use. All that lighting and air conditioning needs power which, depending on how it's generated, can contribute to CO2 emissions. But progress is being made on this front, according to Kozai.

    "Costs of lighting and air conditioning accounted for 30% of total (PFAL) production costs five years ago. The figure is 20% or lower now and will fall to 15% within five years" due to improved LEDs, selection of plant types, and other factors, he projected.

    Vertical farming operations are sprouting up across the world, while major projects in Japan have backing from the likes of telecoms giant NTT Group and energy conglomerate Eneos Group. But one prime example of vertical farming's promise can be found over the ocean, in Canada's far northern Yukon Territory. There, entrepreneur Sonny Gray is on the verge of making fresh vegetables in the middle of a frigid Yukon January a reality.

    Gray's North Star Agriculture is set to launch an industrial-scale vertical farm in the Yukon capital of Whitehorse. Heated by water from a nearby hot spring resort, it will deliver fresh greens to a community that now must depend on greens from the United States or Mexico to get through the winter -- vegetables rendered far less nutritious after days and days on the road.

    "When it comes to indoor farming, rain, snow, whatever, we're fine. Which is why we're doing it," Gray told The Mainichi. "One of the reasons why we would start shifting and doing agriculture in a more controlled environment is because the environment right now is out of control. Climate change is an actual thing that we see here in the North on a regular basis. There are pretty massive fluctuations," he continued. "I don't know what we're going to get tomorrow for weather. It could be anything."

    If successful, Gray will be helping improve the health of his community, boost the local economy, and cut greenhouse gas emissions by eliminating the need for trans-continental shipping. It's a pattern we may see spread across our planet as we learn to keep ourselves happy and healthy in the face of an uncertain environmental future.

    (By Robert Sakai-Irvine, The Mainichi Staff Writer)

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