In 1963, when Cheng Xiangwen was assigned to work as a seed cultivation technician at a farm in Henan province's Xunxian county, corn production in the area was just above 750 kilograms per hectare.
Even though the farmers worked hard, they could not harvest enough corn, a food staple, to feed their families due to low yields. The situation hit home with Cheng, who had just graduated from vocational school.
"After that, I made up my mind to cultivate new corn varieties so the land would produce more grain," said 84-year-old Cheng, chief expert in corn cultivation at the Hebi Academy of Agricultural Sciences in Henan.
In 1964, to speed up the process of finding and cultivating new varieties, Cheng embarked on a trip to the tropical city of Sanya, Hainan province, more than 2,000 kilometers to the south.
Over the next five decades, Cheng traveled between Xunxian and Sanya every year. Before the winter's cold took hold in Xunxian, he arrived in Sanya to conduct cultivation work on corn varieties. In the spring, he returned to Xunxian to grow the corn seeds that had been developed in Sanya during the winter.
Cheng and his colleagues have developed 39 new corn varieties that have significantly improved corn production in Xunxian and many other parts of the country since the 1960s. Xundan20, one of the varieties, produced a yield of nearly 13 metric tons per hectare in Hebi in 2009, a record for Henan.
"I have been doing just one thing since starting work in 1963 and that is to breed corn varieties," said Cheng, who won a national award for progress in science and technology in 2011. "My greatest wish has been to breed better corn varieties to contribute to national food security."
Cultivating secure, stable and advanced seed varieties is key to China's ongoing efforts to beef up food security, especially in the context of the COVID-19 pandemic, during which ensuring food supplies is crucial to every country.
The annual Central Economic Work Conference last month put the growth of the seed sector and establishment of seed banks high on the nation's economic agenda for this year.
The conference designated seed protection, research and development as one of eight key economic tasks.
Empowering the seed industry was also listed as a priority in order to improve food security.
Top leaders urged intensified efforts to achieve scientific and technological breakthroughs in seed cultivation, along with the protection and utilization of genetic resources.
Following decades of sustained effort, China has successfully secured food supplies for its population, the world's biggest. Grain production reached 670 million metric tons last year, a year-on-year increase of 0.9 percent and a record high despite the effect of COVID-19, according to the National Bureau of Statistics.
Increases in grain production have been driven largely by the promotion of superior species.
Wan Jianmin, vice-president of the Chinese Academy of Agricultural Sciences, said superior crop varieties have contributed to more than 45 percent of the total increase in grain production over the past five years.
China has achieved self-sufficiency in wheat and rice. All varieties of the two crops grown in China have been domestically developed, and their yields are higher than those in most countries, Wan said.
Cheng said: "Seeds are the foundation of agriculture. They are like the (computer) chip of modern agriculture and are crucially important to a country's food security."
Tang Renjian, minister of agriculture and rural affairs, said China has made great progress in developing the seed industry in recent years. Domestically developed crop varieties account for more than 95 percent of the total area of agricultural planting in China.
Although China is largely self-sufficient in seed supplies for major crops such as rice, wheat, corn and soybeans, it still relies on imports of seeds for certain agricultural products and livestock, said Li Xinhai, a scientist who studies the corn industry at the Chinese Academy of Agricultural Sciences.
Although China is home to many pig species and is the world's biggest producer and consumer of pork, it relies on imported pigs for breeding, as some species boast characteristics such as growth rates that are faster than those of domestic breeds.
Wan said a major task for the seed industry is to develop varieties that are not only more productive, but include characteristics such as being environmentally friendly.
Although rice yields in China are high, the quality is lower than varieties from Japan and Thailand. Rice varieties in China need to be further improved to meet people's increasing demand for high-quality food, Wan said.
"In addition, we must develop new species that are resistant to diseases and pests, so no pesticides need to be used for farming, and that also conserve water." Wan added that food security can only be achieved by improving crop cultivation technologies.
Wu Cunxiang, a soybean researcher at the Chinese Academy of Agricultural Sciences, said of all major crops in China, soybean production is most reliant on imports. More than 80 percent of soybeans consumed domestically are imported, and most of them are used as raw materials for edible oil and animal feed.
China still lags behind some other countries in technology to cultivate soybeans, resulting in lower yields. In the United States, for example, technology to produce genetically modified soybeans is used extensively, but that same technology has been given only limited approval for use in China yet.
Despite some difficulties, researchers have been making progress in developing GM technology, and some new soybean varieties are undergoing tests, he said.