Bright green lettuce leaves are ready for picking, while ripe red tomatoes bow their stalks. Natural produce as they seem to be, the lettuce is grown inside an artificially lit plant factory, while the tomatoes are cultivated inside a solar plant factory, both operated by Chiba University.
Chiba University is a pioneer in this area, having over a 30-year history in growing plants hydroponically. Now operating five solar plant factories and two artificial light plant factories, the university stresses the importance of such factories.
One reason is due to the drastic changes in the distribution and consumption systems of Japan, as an increasing number of people are deciding to eat out, coupled with the increasing trend of importing fresh produce and vegetables from other countries regardless of their high prices.
Another serious problem that Japan faces is “a critical shortage of next-generation farmers, together with the sharp increase in the elderly population,” says Toru Maruo, a doctor of agriculture and professor at the Graduate School of Horticulture, Chiba University. Maruo is also a key player in the vegetable plant factory project that is participated in by over 60 corporate entities.
According to government statistics, the average age of farmers in Japan was 66.5 years in 2013, of which 46.8 percent were 70 or over. As Japan’s population aged 39 years or younger is below 5 percent, the number of Japanese farmers in 10 years will dwindle to about one-third the figure of today; a drastic reduction never experienced by any nation in history.
“In order to respond quickly and confidently to such conditions, we must establish a way in which large-scale, planned, rational, efficient and pesticide-free farming can be undertaken, while minimizing the risk of product tampering,” stresses Maruo.
And since there is no stopping Japan’s population decrease and aging, Maruo suggests plant factories should be built and put into practical use in the coming five to ten years.
Especially for fresh agricultural produce such as vegetables in which “freshness” counts, production near the volume-consuming mega cities like Tokyo makes sense and is most suitable.
Technically speaking, a plant factory systematically achieves high-quality, year-round production by installing equipment that maintains the optimal conditions for vegetable growth. This includes control of temperature, artificial lighting such as fluorescent and LED, moisture, air and CO2 density. Furthermore, the factories use solutions instead of soil to control nutrient delivery while cultivating the produce.
At the artificial light factory, the initial challenge of producing good, consistently high-quality produce had been overcome relatively easily and 80 to 100 grams of leaf lettuce can be harvested ten days after planting. The second challenge was to reduce costs. To this end, Chiba University simplified the workflow and experimented with various lighting and air conditioning methods until its lettuce factories could better the cost of ¥700 per kilogram.
At the solar facilities, meanwhile, tests have been conducted on a high-yield tomato production system. By planting seeds densely and using finely tuned environmental controls, Chiba University’s tomato plant factory now achieves 2.5 times the average yield of tomatoes of Chiba Prefecture.
Another eye-catching development in this area is the recent production of nutrient-fortified vegetables. By adjusting the nutrient solutions and through lighting innovations, some vegetables can now be produced at Chiba University’s plant factories to meet the health requirements of certain consumers. For example, low-potassium lettuce can now be produced for kidney disease patients who must control their potassium intake. Such innovation could be defined as a new chapter in plant factories that bring fresh produce production closer to medicine.
Regarding the future, Maruo seeks to establish a system that allows large harvests with a minimal investment of resources and energy.
“We also seek to undertake technological development that keeps the load on the environment to a minimum,” he says.
Looking at the global scale, the need exists for altered agricultural production methods, as the population of farmers decreases, society ages and more people look to live in cities. Consequently, an increased number of plant factories are planned in urban areas throughout the world in the coming years. Furthermore, since these factories require much less fertile land than standard farms, they are likely to be in densely populated areas, cold weather regions and deserts. “When that happens, I hope Japan can serve as the role model,” Maruo says. Already leading the world in this area, Maruo hopes the technological and human infrastructure is concentrated for further, long-term worldwide R&D activities in this field.
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