Chinese exports are plummeting amid the economic crisis and migrant workers such as Liu Xiao are returning home to impoverished villages. Link to this video

Until a week ago, Liu Xiao was part of the Pearl river delta’s army: one of the thousands of workers streaming along a Shenzhen road, gulping down breakfast, texting, lighting a final cigarette, teasing friends and swapping gossip – rushing rushing rushing to the factory for another shift making bras, computers and plastic toys for the world.

Today she waits patiently at the railway station across town. This region was the motor of China’s economic boom, but plummeting exports have forced it to slow and millions of those who kept it running have given up and gone home. Liu Xiao is one of the latest to return to the countryside: in her case to a village of just 200 people a 10-hour ride – and a world away – from Shenzhen.

For a year and a half she worked 11-hour days checking hard drive casings with no music or chat permitted, but found satisfaction in spotting hairline cracks and other errors. Home was a dormitory shared with seven other girls, crowded but renao (lively and chaotic).

“There were lots of rules, like no cooking and not being loud, but you get used to it,” she says. “It was harmonious, not like other dormitories where everyone quarrels.”

Production began to slow late last year and workers drifted away. Without overtime Liu Xiao’s wages slipped from 2,500 yuan (£240) a month to 800 yuan, barely covering living costs, and leaving nothing for visits to internet cafes or for the shopping trips she had learned to enjoy.

Millions abandoned the city at Chinese new year in late January and a steady trickle continues. When rumours spread that Liu Xiao’s factory would soon go bankrupt, as thousands across the manufacturing region have done, she handed in her notice.

Now she is killing time with a colleague, waiting for the night train. “I’m not too happy,” she says. “There aren’t many factories near my village. It’s too boring; there’s not much entertainment and it’s difficult to get out.”

Thirty years ago, Shenzhen was not so different to home: a small fishing village marked out only by its proximity to Hong Kong. That was enough to make Deng Xiaoping pick it as the first special economic zone.

Now it is a restless, dense city of strangers, drawn from every part of China. It has five-star hotels, a Gucci store, endless blocks of shops and flashy restaurants, but also acres of factories and cramped dormitory blocks, sprawling into the next industrial town. Its population has increased more than 30-fold. Even according to official figures, which most consider a wild underestimate, it has 10 million residents.

Three decades after Deng’s economic reforms began, China can seem like two nations. There are the sky-scraping neon-lit cities such as Shenzhen and then there is the countryside, still home to most of the population and richer by far than it was, but falling ever further behind the urban world. Average incomes in cities are now more than three times those of the countryside.

This gulf has produced 140 million migrant workers, and without them the gap would be far wider. For many, their years of toil are a painful, enforced exile from families, undertaken to ensure healthcare for ageing parents, an education for their children and a home for the family.

Increasingly, for younger people, the journey from farm to factory is also a voyage of self-discovery. China as a nation is increasingly urban, wealthy and demanding – and so are many of its citizens.

By Tania Branigan from guardian.co.uk