Chengdu vertical farm takes agriculture to new heights

Technicians monitor the growth of strawberries in an automated vertical plant factory in Chengdu, Sichuan province. [Photo provided to China Daily]

High-tech automated facility can produce 50 tons of lettuce annually

In an 8.8-meter-tall automated plant factory in Chengdu, Sichuan province, rows of lettuce bathe in red light on 20-layer cultivation racks and grow at twice the normal rate.

The vertical farm facility, covering just 100 square meters, was developed by the Institute of Urban Agriculture of the Chinese Academy of Agricultural Sciences. It can produce up to 50 metric tons of lettuce annually.

"The factory enables full control over light, temperature, water, nutrients and air. The entire production process, from seeding and transplanting to harvesting and packaging, is handled by robots," said staff member Shi Xianglian.

Shi said the growth cycle for lettuce here is only 30 to 35 days — half the time needed in traditional open-field farming — while yield per unit area can reach up to 120 times that of conventional methods.

With soilless cultivation in a sterile environment, the system eliminates pests and diseases, ensuring the produce is free of heavy metals, chemical additives and pesticide residues, she added.

Wang Sen, a researcher at the institute, said a core technology of the vertical farm is the use of artificial light to ensure efficient photosynthesis. He explained that LED lights are used to offer specific "recipes" — varying in color, intensity and duration — to suit different plant species and growth stages. After years of research, the institute has developed over 1,300 such light formulas. "Despite the high production efficiency, operating costs remain a bottleneck," Wang said, noting that electricity for artificial lighting and temperature control accounts for about 70 percent of total operating expenses.

"Currently, producing one kilogram of lettuce in such a facility costs between 10 and 15 yuan ($1.5-2.2), significantly higher than traditional methods," he added.

A technician checks the growth of strawberries in the plant. [Photo provided to China Daily]

For now, commercialization of such a facility is economically viable only in densely populated cities with high consumption levels and low vegetable self-sufficiency.

Using the core technology of the vertical plant factory, the institute has supported its partners in growing vegetables in converted shipping containers abandoned in the desert around the deep-water port of Doha in Qatar. During the FIFA World Cup Qatar 2022, 70 to 90 percent of the vegetables supplied to athletes were grown in those containers.

"Multiple companies in Saudi Arabia and the United Arab Emirates have reached out to us in recent years to explore cooperation in this field," Wang said.

Domestically, a partnership was signed at the end of last year with a company in the Hong Kong Special Administrative Region to establish a vertical farm. Set to begin operations in the second half of 2026, it will produce vegetables and conduct agricultural study tour programs.

Beyond vegetables, vertical farming technology is being applied to higher-value crops to achieve commercial viability.

In Wenjiang district of Chengdu, a 2,300-square-meter vertical strawberry farm with 11 layers began operations in July and yielded its first harvest in September. Its annual output can reach 73 tons, which is 30 to 40 times that of conventional open-field strawberry farming.

"Traditionally, strawberries are only grown from winter to spring in Chengdu, but this factory enables year-round production of high-quality strawberries," said Peng Jie, chairman of Sichuan Zhongnong Yixiang Agricultural Technology Co, which operates the farm.

Although the growth cycle is shortened to about 30 days, the strawberries boast superior taste, thanks to artificial intelligence enabled precise regulation of light and temperature, which accelerates sugar accumulation, Peng said.

The 100-square-meter facility is capable of producing 50 metric tons of lettuce annually. [Photo provided to China Daily]

Despite high costs in equipment, energy consumption and R&D, the farm's strawberries command premium prices ranging from 200 to 400 yuan per kilogram — several times that of regular strawberries — due to their rare varieties and exceptional safety standards: zero pesticides, hormones, or heavy metals.

Another crucial application of vertical farming technology is accelerating crop breeding.

"Previously, researchers had to travel to tropical Hainan province to accelerate crop breeding. Now, this can be achieved right here in our plant factory," Wang said. "Through precise coupling control of light, temperature and nutrients, the growth cycle of crops such as rice and wheat can be shortened by half or more."

Looking ahead, Wang said their focus will be on reducing energy consumption and fixed investment costs to facilitate broader commercial adoption.

"If controlled nuclear fusion is realized in the future and leads to a significant drop in electricity costs, plant factories will undoubtedly achieve large-scale implementation," he added.