Yang Qichang walks through his “plant factory” atop the Chinese Academy of Agricultural Sciences in Beijing, inspecting trays of tomato vines that may help farmers slip the stranglehold that toxins have on China’s food supply. The containers are stacked like bunk beds, with each vine wrapped in red and blue LED lights that evoke tiny Christmas trees. Yang is testing which parts of the visible-light spectrum are optimal for photosynthesis and plant growth while using minimal energy. He’s having some success. With rows 10 feet high, Yang’s indoor patches of tomatoes, lettuce, celery and bok choy yield between 40 and 100 times more produce than a typical open field of the same size. There’s another advantage for using the self-contained, vertical system: outside, choking air pollution measures about five times the level the World Health Organization considers safe. “Using vertical agriculture, we don’t need to use pesticides and we can use less chemical fertilizers—and produce safe food,” said Yang, director of the Institute of Environment and Sustainable Development in Agriculture. Yang’s government-funded research on vertical farming reflects the changing mindset of China’s leaders, who for decades preoccupied themselves with raising incomes for 1 billion-plus people. Runaway growth created the world’s second-biggest economy, yet the catalyzing coal mines and smokestacks filled the environment with poisons and ate up valuable farmland. That stew inhibits the nation’s ability to feed itself, and is one reason why China increasingly relies on international markets to secure enough food. For example, it imported about $31.2 billion of soybeans in 2015, an increase of 43 percent since 2008, according to the National Bureau of Statistics. About a third of that came from the U.S. Given the fluctuating state of trade relations with U.S. President Donald Trump’s administration and the increasing global competition for resources, China is turning to technology to make its land productive again. “We will undertake rigorous investigations on soil pollution, and develop and implement category-based measures to tackle this problem,” Premier Li Keqiang told the National People’s Congress in March. The silver bullet would be to eliminate emissions and industrial waste, an unrealistic option for a developing $11 trillion economy. Yet inventors and investors believe there are enough promising technologies to help China circumvent—and restore—lost agricultural productivity. Government money backs a variety of efforts to modernize farming and improve growers’ livelihoods. The state-run Agricultural Development Bank of China pledges 3 trillion yuan ($437 billion) in loans through 2020 to finance key projects promoted by the Ministry of Agriculture. By comparison, the value of U.S. agricultural production last year is forecast to be $405.2 billion. Favorable terms will be offered to projects trying to improve efficiency, increase the harvest, modernize farming operations and develop the seed industry to ensure grain supplies, the bank said. The loan program also intends to stimulate overseas investment in agriculture by Chinese companies. The biggest example would be state-owned China National Chemical Corp.’s planned acquisition of Switzerland’s Syngenta AG for $43 billion. That will give ChemChina access to the intellectual property, including seed technology, of one of the largest agri-businesses. Yet China is reluctant to unleash genetically modified foods into its grocery stores. The government doesn’t allow planting of most GMO crops, including pest-resistant rice and herbicide-resistant soybeans, especially as an October survey in the northern breadbasket of Heilongjiang province showed that 90 percent of respondents oppose GMOs. China will carry out a nationwide poll on the technology next month. “China’s past food-safety problems have caused the public to distrust the government when it comes to new food technologies,” said Sam Geall, an associate fellow at Chatham House in London. About a fifth of China’s arable land contains levels of toxins exceeding national standards, the government said in 2014. That’s more than half the size of California. About 14 percent of domestic grain is laced with such heavy metals as cadmium, arsenic and lead, scientists at government-affiliated universities wrote in 2015. The danger is most evident in industrial coastal provinces, where many of the world’s iPhones and Nikes are manufactured. The government of Guangdong province, adjacent to Hong Kong, said in 2013 that 44 percent of the rice sampled locally was laced with excessive cadmium, which can damage organs and weaken bones if consumed regularly in high quantities. That’s where Yang’s “plant factories” would come in. For now, the greenhouse-like structures are mostly demonstrations as he tries to improve their energy efficiency and make their produce more affordable to consumers—and a better investment for the government. Yang’s work is supported by an $8 million government grant. “With the challenges our agriculture is facing, including China’s rapid urbanization and the increasing need for safe food, plant factories and vertical agriculture will undergo a big development in China,” he said. “There will be many ways to farm in big cities.” He isn’t alone in hunting for techniques to grow untainted food in the concrete jungle. A Beijing startup called Alesca Life Technologies is using retrofitted shipping containers to farm leafy greens. A demonstration model is parked atop metal stilts in an alley between a Japanese restaurant and a block of office buildings in Beijing. Inside, co-founder Stuart Oda, a former investment banker for Bank of America Merrill Lynch in the U.S. and Japan, checks on rows of planters sprouting peas, mustard, kale and arugula under LED bulbs. Alesca Life’s smartphone app allows growers to monitor air and water conditions remotely. “Agriculture has not really innovated materially in the past 10,000 years,” Oda said. “The future of farming—to us—is urban.” The containers can sell for $45,000 to $65,000 each, depending on the specifications, Oda said. Alesca Life sold portable, cabinet-sized units to a division of the Swire Group, which manages luxury hotels in Beijing, and the royal family of Dubai. The startup hasn’t publicly disclosed its fundraising. Shunwei Capital Partners, a Beijing-based fund backed by Xiaomi Corp. founder Lei Jun, has invested in 15 rural and agriculture-related startups in China, including one that makes sensors for tracking soil and air quality. Shunwei manages more than $1.75 billion and 2 billion yuan across five funds. “For agriculture technology to be adopted on a wider scale, it needs to be efficient and cost-effective,” said Tuck Lye Koh, the founding partner. That’s one reason why Shunwei is backing agricultural drones, which more precisely spray fertilizers and the chemicals that ward off crop-destroying pests and diseases. As China’s farmland dwindled because of urbanization, the remaining growers attempted to boost yields by soaking fields with fertilizers and pesticides, degrading the soil and contaminating the crops. Farmers in China use four-and-a-half times more fertilizer per hectare (2.4 acres) of arable land than farmers in North America, according to the World Bank. “There’s overuse of fertilizers in every country, but especially China,” said Jeremy Rifkin, whose books include “The Third Industrial Revolution.” “The crops can’t even absorb the amount of fertilizers that are being dumped.” As dawn squints over cornfields on Hainan island, a pastel-blue truck rumbles down the gravel road and stops. Workers emerge with a pair of drones made by Shenzhen-based DJI and a cluster of batteries. Zhang Yourong, the farmer managing 270 mu (44 acres), arrives in a pickup loaded with pesticide bottles. The crew adds water and pours the milky concoction into 10-liter plastic canisters suspended under the drones. The stalks part like the wake of a boat as the drones fly over. Every 10 minutes, the eight-armed machines return, and the crew refills canisters and changes batteries. Zhang used to hire four or five workers to walk the fields with backpack sprayers for five days. Now, the drones cover his crops in a morning and use 30 percent less chemicals, he said. That’s what the government needs to hear as it tries to make China’s food supply safer. “This is much easier and much faster than before,” Zhang said. “This is the future. Many farmers are switching.”