At the Baojia industrial park in Pengshui Miao and Tujia autonomous county of Chongqing, production lines of the Miao Potato Agricultural Co are busy, as machines carry out mixing, steaming, cutting and packaging processes before rolling out bags of hotpot powder made from sweet potatoes.

Workers move swiftly, ensuring that every process is meticulously followed to produce the best sweet potato starch.

According to production manager Sun Zhen, the company has become the largest sweet potato industrial enterprise in western China.

"We can leverage Pengshui's 20,000 hectares of sweet potato land. Our 500-odd production and technical staff members work on our most advanced and fully automated production and factory buildings spreading across an area of about 40,000 square meters," he said.

"We can produce 21,000 metric tons of sweet potato products annually, with yearly sales topping 200 million yuan ($28.3 million), helping customers use it in hotpot cuisine," he said.

The company's products are sold in provinces including Hunan, Hubei, Henan, Hebei, Zhejiang, Fujian, Yunnan, Guizhou and Sichuan, he said.

As one of 100 key counties involved in comprehensive desertification control across China's karst areas, Pengshui started to restore forest and green vegetation from 2011, trying to enrich local farmers.

Sun said Pengshui has invested 150 million yuan this year to boost deep processing of potato starch, set up a high-yield sweet potato planting base and breed new varieties.

Ge Xianping, manager of Pengshui Longxu Jingsi Sweet Potato Starch Factory, has been involved in the sweet potato starch industry for over 30 years. She said the hot and sour powder made from sweet potato starch is a well-known delicacy.

Handmade sweet potato starch made by local farmers flourished during the Qing Dynasty (1644-1911), and is being dubbed a "treasure in the mountains," she said.

Her factory processes over 8,000 tons of fresh sweet potatoes annually, and its annual sales revenue exceeds 40 million yuan, she added.

Zhang Xiaohong, chief of State-owned Pengshui Supply and Marketing Cooperatives, said Pengshui has in recent years adopted sweet potato as a lead industry for rural vitalization.

"Pengshui Jing Si Sweet Potato Starch, known for its quality and great taste, has become the flagship product of this industry," he said.

By upgrading the sweet potato industry and producing higher quality sweet potato starch, Zhang said Pengshui is developing a modern and highly efficient agriculture system that grows produce such as sweet potatoes and Chinese medicinal herbs.