Cultivation of sweet potatoes brought in 420 million yuan last year

A county in China's southernmost province of Hainan has used modern planting techniques to turn its formerly barren sandy soil into a hotbed for cash, with its sweet potatoes becoming a global brand.

Standing on the edge of a field, Wang Wenke took telephone orders from across the country as he oversaw the harvest on a sunny day in Chengmai this month.

Realizing the profit potential of sweet potatoes, university graduate Wang, the son of a farmer, returned home in 2007.

"I just kept thinking about the fantastic taste of the sweet potatoes," he recalled, adding that the county's selenium-rich soil is another reason he was confident of the vegetable's market prospects.

Chengmai is renowned for the longevity of its residents and is home to more than 200 centenarians, due, in part, to its selenium-rich crops.

Sweet potatoes produced in the county are nutritious, delicious, relatively uniform in shape, have a high yield and sell at 52 yuan ($7) per kilogram, 10 times the average price for the vegetable.

Yang Yingchun, deputy Party chief of the county, recalled a local agricultural company importing Japanese sweet potato seedlings that suited the sandy soil in 1996, but planting was not a widespread practice until Wang's return.

Using the seedlings, Wang sought help from the Hainan Academy of Agricultural Sciences, which developed virus-free seedlings.

Under a microscope, seedling are cut to just 0.2 millimeters to eliminate viruses, which has ensured a yield increase of 30 percent, and improved taste and shape.

The method of planting is also different. The soil is humid and abundant in organic materials, so no chemical fertilizer is needed. Farmers plant the seedlings 20 centimeters apart on a 40-cm-high ridge.

"The distance between the seedlings leaves space for growth that helps ensure the uniformity of size of each sweet potato," Wang said. The technique was quickly copied after Wang made 200,000 yuan in profit on a plot of 6 hectares in the first year.

Last year, the total coverage of sweet potato farmland in Chengmai had reached 1,600 hectares, with a yield of 42,000 metric tons bringing in 420 million yuan.

China aims to eradicate poverty by 2020. It has lifted 700 million people out of poverty in the past 30 years, but relief work is likely to become increasingly difficult as it nears its end.

There were still 43 million people living in poverty last year, mostly in rural areas.

To maximize profits from sweet potato sales, Wang's township registered a sweet potato brand in 2009, designing uniform brand packaging of the vegetable, according to Shen Xinxia, Party chief of Qiaotou township.

The county government regularly organized branding activities and helped set up a sweet potato research institute.

A total of 184 online outlets have brought in annual sales of 30 million yuan, including 10 million yuan from overseas.

Benefiting from the sweet potato industry, annual income per household reached 80,000 yuan in the township last year, with the number of impoverished households reduced from 1,390 in 2007 to 19.

Shen said the sweet potatoes are sold to major supermarket chains across China, including Carrefour and Wal-Mart, and exported to countries such as Canada, Japan and Singapore.

Similar production flows are being utilized for lychees, grapefruits and oranges.

"With a standard agricultural production flow, sweet potatoes are produced like industrial parts, which has become a characteristic of our county's agriculture," said Yang Sitao, the county's Party chief.