HAIKOU, April 19 (Xinhua) -- A county in China's southernmost province of Hainan has made its sweet potatoes into a global brand.
Using modern planting techniques, Chengmai County has turned its formerly barren sandy soil into a hotbed for cash.
Standing on the edge of a field, Wang Wenke took phone orders from across the country as he watched the harvest on a sunny April day.
Sweet potato produced in Chengmai County is nutritious, delicious, relatively uniform in shape, has a high yield and sells at 52 yuan (7.5 U.S. dollars) per kilogram, 10 times the average for sweet potatoes.
Seeing the profit potential of the sweet potato, university graduate Wang, son of a local farmer, returned home in 2007.
"I just couldn't forget the fantastic taste," he recalled, adding that the selenium-rich soil is another reason he was confident in the market prospects.
Chengmai is renowned for the longevity of its residents and is home to over 200 centenarians, partly thanks to its selenium-rich crops.
Yang Yingchun, deputy Party head of the village, recalls a local agricultural company imported Japanese sweet potato seedlings that suited the local sandy soil in 1996, but planting was not widespread until Wang's return.
Using the seedlings, Wang sought help from Hainan Academy of Agricultural Sciences, which developed virus-free seedlings.
Under a microscope, a seedling is cut to only 0.2 millimeter to eliminate viruses, which has ensured a yield increase of 30 percent and better taste and shape.
The method of planting is also different. The soil is humid enough and abundant with organic materials so no chemical fertilizer is needed. Farmers plant the seedlings every 20 cm on a 40-cm-high ridge.
"The standard distance leaves growth space which helps ensure uniformity of size of each sweet potato," said Wang. The technique was quickly copied when Wang made 200,000 yuan profit on six hectares in the very first year.
Last year, total coverage of sweet potato farmland had reached 1,600 hectares. The township secured a total yield of 42,000 tonnes last year, bringing in 420 million yuan.
China aims to eradicate poverty by 2020. It has lifted 700 million people out of poverty over about 30 years, but in the coming years poverty relief work will become increasingly difficult as it nears its end. There were still 43 million people living in poverty last year, mostly in rural areas.
The "No. 1 central document" issued in January encouraged supply-side reform in agriculture to increase the output of high-quality products based on green and innovative production.
A group of innovation centers and alliances will be created, and outstanding research will be rewarded, according to the document.
To maximize sweet potato sales profit, Wang's village registered a sweet potato brand in 2009, and organized uniform packaging of the brand, according to Shen Xinxia, Party head of Qiaotou Township.
The local 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 had reached 80,000 yuan in the township. The number of impoverished households reduced from 1,390 in 2007 to 19 in 2016.
Shen says their sweet potatoes are sold to major supermarket chains like Carrefour and Walmart across China, and exported to countries such as Canada, Japan and Singapore.
Similar production flows are being utilized for lychee, grapefruit and orange production.
"With a standard agricultural production flow, sweet potatoes are produced like an industrial part, which has become a characteristic of our county's agriculture," says Yang Sitao, Party head of Chengmai County.
