With a postgraduate degree, Shen Haimei could have chosen to make a fortune doing a regular office job. Instead, she has chosen to work with manure and offer organic fertilizers to farmers, free of charge. Shen, 45, an overseas returnee, is pursuing green agriculture in Harbin city in northeast China's Heilongjiang province.

Inside a huge gray capsule on Qingyuan Farm, 6,000 cubic meters of manure are under fermentation.

"It will turn into organic fertilizer in six months, and be applied to nearby farmland," she said.

Six years ago, she quit the dairy company where she had worked for over a decade, to study agricultural economy at Aarhus University in Denmark.

"Dung disposal facilities were way behind the increasing number of farms in China," she said. "Dung should not become a burden for the environment. We must figure out a way to make use of it."

When interning for an agricultural technology outreach center in Denmark, she was impressed by their advanced technology for disposing livestock dung.

"A truck was applying liquid manure fertilizer to farmland efficiently. Farmers recorded down the exact time and quantity of fertilizer added. All of this was new to me," she said.

She decided to bring what she had learned back to China and establish her own green business.

But after visiting nearly 100 farms, she was frustrated by the pollution caused by livestock dung and the huge waste of the resource, due to livestock raising being separated from farming in China.

"In the past, farmers did farming and raised some pigs or chicken at the same time. Livestock manure was used on their own land," she said. "But large scale farming has separated them."

In 2014, she started a company to re-connect farming with raising livestock, making personalized plans on dung disposal for each farm.

At the beginning, her idea was not welcomed by farmers. She knocked on the door of every farmer she could reach.

"I explained to them how excessive chemical fertilizer use would lead to soil degradation and low fertility, but organic fertilizers could make the soil soft again and increase productivity."

Over the years, agricultural experts repeatedly warned that the precious black soil in China's northeast, which was once fertile, had been degraded due to excessive use of chemical fertilizers and long-term cultivation, threatening stable output.

Now, with Shen's help, farmers are witnessing real changes in their land - soil becoming soft and loose, and production increasing.

Last year, Qingyuan Pig Farm joined Shen's efforts in developing the capsule technology to dispose around 12,000 cubic meters of pig manure a year.

Nestle Corporation also found her and reached a cooperation plan to dispose 80,000 cubic meters of manure a year in 10 capsules.

Making money has never been her priority.

"It is more important to develop the industry to turn dung into fertilizer, and encourage the use of organic fertilizers. This benefits the environment and agriculture in the long term."

China is making efforts to scale back use of chemical fertilizer and switch to organic alternatives.

According to local authorities, Heilongjiang plans to cut the use of chemical fertilizers, pesticides and herbicides from 2015 levels by 10, 20 and 30 percent respectively by 2020.

With 1.25 million yuan ($180,800) in financial support from the local government, Shen is now spreading organic fertilizers on 367 hectares of land.

Her green business has attracted young environmentalists, which has delighted her.

"I will continue to improve the technology with what I have learned abroad and hope to see China set a green standard for modern agriculture," she said.