URUMQI - Li Zhengxin, a 51-year-old farmer in Burqin County in northwest China's Xinjiang Uygur Autonomous Region, has seen his life completely changed by a plant over the past few years. He calls it the "money tree."

Sea buckthorn, a kind of shrub whose fruit is known for its richness in vitamin C, has brought him an annual profit of more than 500,000 yuan (72,500 U.S. dollars).

Before planting sea buckthorns in 2012, Li earned less than 50,000 yuan a year by planting forage and other crops.

"I never expected sea buckthorn to be my money tree," he said.

Six years ago, the county government began to encourage local farmers to grow sea buckthorn to increase their income.

Li financed 200,000 yuan, most of which with debt, to sign a contract for 600 mu (40 hectares) of sea buckthorn in 2012, which was quite risky considering his financial situation at that time.

"Sea buckthorn does not bear fruits in the first three years, during which I made almost nothing," he said.

Thanks to the supportive policy of Burqin County which provides a subsidy of 200 yuan for each mu of sea buckthorn in the first three years, Li's financial burden was greatly eased.

Li now harvests tens of tonnes of sea buckthorn berries every year.

As the soil and weather in the region are suitable to grow sea buckthorn, Burqin County has about 100,000 mu (6,700 hectares) of the shrub.

"Farmers can earn a net income between 1,200 yuan and 1,500 yuan for each mu of sea buckthorn annually," said Wan Junmin, the head of the agricultural bureau of Burqin County.

The county government has also invited Huiyuan, China's top juice maker, to purchase local farmers' berries.

"Sea buckthorn has not only become the cash cow for local residents, but also protected our county's environment," said Wang Gangyi, head of the forestry bureau of the county.

Burqin County has long suffered from severe sandstorms. Since the plant can lessen the force of the wind and stabilize moving sand, sea buckthorn plays a significant role in the protection of the county's biological environment, according to Wang.

Sea buckthorn has also become a key element in the development of tourism of the county. In October, Burqin County will hold a sea buckthorn festival to promote its agricultural tourism.

Li plans to build a fruit picking garden for tourists, hoping to develop agritainment featuring sea buckthorn in the future.

"The little fruits of sea buckthorn have become a huge industry," he said.