Plant factories are facilities that produce high-quality vegetables (mostly leafy greens) throughout the year by artificially controlling the light, temperature, humidity, CO2 concentration, and culture solution of the growing environment. This innovative farming method allows growers to better plan production and produces vegetables roughly two to four times faster than traditional farming.
The high-tech, automated systems of plant factories make them great for commercial growing. These facilities facilitate the use of grow trays, which growers stack on top of each other. Grow lights provide warmth and sunlight for photosynthesis, and the closed environment protects crops from uncontrolled variables like climate and pests.
The growing process is automated from beginning to end and is “conducive to economies of scale in order to control cost, quantity, and quality against the required harvest time.” This gives food producers the chance to determine the sale price like other large-scale industrial factories.
The components that make up a plant factory include a well-insulated, airtight, windowless structure similar to a warehouse. It also contains shelves with a light source and culture beds, units for carbon dioxide, nutrient supply, and environmental controls, air conditioners, and other equipment for sterilizing nutrient solutions, circulating air, and seeders.
Plant factories differ from greenhouses in several ways. First, plant factories are nearly 100% automated, where greenhouses may have some human labor during the growing and production process. Second, while greenhouses are suitable for growing a wide variety of plants and flowers, plant factories so far are only viable in growing leafy vegetables such as lettuce, arugula, and basil. Third, plant factories are not yet a common feature in innovative farming, though that may change.
Japan is home to more plant factories than in any other country. This is due to government subsidies and rapid commercialization of facilities in 2010 to drive interest in plant factories and help Japan become less reliant on Chinese products, which is grown using large amounts of pesticides. As of 2014, 70 of the 170 plant factories in Japan produced more than 1,000 heads of lettuce every day, with about ten facilities producing upwards of 10,000.
There are some benefits from plant factories, even over greenhouses. Regardless of the weather, facilities can see upwards of 10 to 100-fold productivity per land area. Since zero chemicals are used in the growing process, there’s no need to wash the produce before eating, and they can remain fresh for a long time.
The disadvantages of this innovative farming method are the limited variety of food that plant factories can currently produce. They are only useful for producing leafy greens, medicinal herbs (as well as regular herbs), and mini root crops like micro carrots and turnips. Therefore, vegetables grown in a plant factory are not a replacement for those raised in a greenhouse or via traditional farming.
Despite the limitations in plant factories, it is a relatively new development in the world of innovative agriculture and has plenty of room to expand in this promising market.