Yufan is a "longevity village" with 46 people over 80 years old in Xiantao, Hubei province. The oldest have lived more than 100 years.

Outsiders have long marveled at the numbers, but until 2013 no one knew the reason. That year, the Hubei Geological Survey found that the soil in Xiantao is naturally enriched with selenium, or Se, one of the 14 essential trace elements that are good for human health.

To better use the natural resources and tap the business opportunities brought by the soil, the Xiantao Se-enriched Industry Development Office was established last year.

"The Xiantao government has made great efforts to promote innovative, eco-friendly planting of Se-enriched rice and beans, and the cooperation with the China Oils and Foodstuffs Corp sets a very good example," said Cheng Guohua, director of the office.

After identifying the Se-enriched soil in Xiantao, COFCO signed a 14-year land transfer contract with farmers to plant Se-enriched rice in Lilinzui village, which is in a suburb of Xiantao.

"We use an efficient rice-sowing method, spreading seeds directly on the land instead of using a nursery and transplantation method. Direct planting can save time and reduce labor costs," said Xiao Fenglin, COFCO Xiantao's production manager.

"We also use an advanced production model that connects the company's planting base with farmers. This can improve labor productivity so that the farmers' income per hectare can increase by 50 to 100 yuan ($7.50 to $15) every year."

To guarantee food security, only organic fertilizers and bio-pesticides can be used. The whole production, including processing, storage and logistics, is mechanized, said Wang Jiuju, vice-president of the company in Xiantao.

In addition to planting Se-enriched rice, Xiantao also has developed Se-enriched food brands, such as Xilaifu bean paste, which embodies people's hopes that selenium will bring blessings to Xiantao.

Yuan Youyuan, managing director of Xilaifu, has invested about 30 million yuan since the company was established in September, and said its profits are about 20 percent.

"Natural, organic, Se-enriched beans in Xiantao are anti-cancer, healthy and can make people live longer. All the beans we use to produce bean paste are collected directly from the farmer and nothing is added."

Local people's incomes have increased significantly since Xiantao started to develop the Se-enriched industry about two years ago. For example, normal rice is about 2.5 yuan per kilogram, but the Se-enriched rice is about 40 yuan per kg.