The old Sony factory in eastern Japan’s Miyagi Prefecture is up and running again. This time around, however, it’s been resurrected as something else entirely: an indoor farm that, at 25,000 square feet, is the largest of its kind.
As is the case with other indoor farms, crops are grown in conditions that hardly resemble conventional agriculture. Here, farmworkers, dressed in white lab coats and face masks, take great care in maintaining a sterile environment to ensure that the vast majority of produce are harvested in a state of optimal freshness.
The humid climate inside is managed with precision and rather than using soil, the plants are raised hydroponically, a method where nutrients and fertilizer is drip-fed and absorbed through recycled water.
But the sprawling Mirai lettuce farm has a significant edge over the rest. In interviews, Shigeharu Shimamura, a botanist who serves as the company’s president, touts that, with just 1 percent of the water that’s used for irrigation, his lettuce grows more than twice as fast as lettuce grown outdoors. This translates to an average of 10,000 heads shipped out each day.
The trick, he says, is in the lighting. Designed by General Electric, the LED fixtures sitting atop each stacked row of lettuce are programmed to automatically adjust their illumination in a cycle that maximizes photosynthesis during the day and breathing at night. Compared to outdoor farms, it’s estimated that artificially accelerating the maturation process can boost crop yields by as much as 50 percent. And while indoor farms typically use florescent lighting, LEDs are much more efficient, consuming 40 percent less energy.
Shimamura also says that lettuce grown at the site are healthier. Having the capability to meticulously engineer how each head is produced allows his team to create a variation of romaine lettuce that contains eight to 10 times more beta-carotene and two times the vitamin C, calcium and magnesium.
“The process for growing Mirai lettuce is leaf type, and not head type, so 95 percent of the portion is edible and can be used conveniently at restaurants for salads and sandwiches,” Shimamura says. They also are quite tasty, he says.
In a way, the company’s newest facility may serve as a working vision of things to come. Researchers have warned that, as access to arable land and fresh water supplies dwindles, commercial agricultural systems will no longer be sufficient to feed a global population that’s expected to exceed 10 billion by 2050.
To remedy the situation, these experts have said, would require moving away from industry practices that have long been wasteful. For instance, while farming accounts for 70 percent of water use, most of it is lost because of inefficient irrigation methods, according to a report by the World Water Forum. A separate report, compiled by Britain’s Institution of Mechanical Engineers, found that roughly half of the world’s produce is discarded, partly because of an abundance of crops failing to meet market standards.
Japan, on the other hand, is home to 380 enclosed farms dedicated to raising not only high-quality lettuce, but also spinach, strawberries and other produce. Local electronics giants Fujitsu, Toshiba and Panasonic have all gotten into the game, converting old factories into high-tech farms. Aiding the nationwide overhaul is the country’s current administration, which has expanded its subsidy and assistance program for those working on “advanced agriculture” projects, such as the one undertaken by Mirai.
“Early tests showed that using LED for growing vegetables works, but the kinds of challenges we would face for using it in a large scale factory was still unknown,” Shimamura says.