SOCUELLAMOS, Spain (Reuters) - "Living in this thing is no good," says Nadezhda, pointing to a wine vat lying abandoned by a litter-strewn patch of waste ground on the plains of central Spain.

Around her, barefoot children scamper between mounds of smoldering rubbish. Flies buzz around their heads.

Nadezhda and about 40 others living in this makeshift camp are ethnic Turks from Bulgaria who came to the vineyards of Socuellamos to pick grapes during the six-week annual harvest.

At night they sleep in 20 or so overturned wine vats -- car-sized concrete barrels dumped on the outskirts of Socuellamos, a farming community in the hot and dusty region of Castilla-La Mancha.

In some of the vats, families of up to seven are crammed onto beds of breeze blocks and foam. Cardboard is used as flooring and a thin flap of fabric over the neck of the vat makes for a front door.

Bulgaria joined the European Union on January 1 but the fact this group traveled across the continent in search of work, and the conditions they live in, is a reminder of the economic gulf between old Europe and some of the bloc's newest citizens.

The filthy camp empties out on a typical weekday, when most of the group go looking for work in the vineyards for around 42 euros ($59) a day.

Nadezhda says her husband would earn 10 lev (5 euros) a day at home in Sliven, southern Bulgaria.

Unemployment in their hometown is high and around 10 percent of Bulgaria's 7.3 million people are seeking work abroad.

"Life here (in Spain) is not good. There's no water, no gas. We have a proper home in Sliven, but no money," shrugs Nadezhda, which means 'hope' in Bulgarian.

She points to bottles used to collect water from a public fountain in the town's central square a few hundred meters away. The toilet is a hastily constructed shed in a field.

WORLD AWAY

The local Bar Madrid is a world away from the Bulgarians' camp just across the field.

Local people have seen the Bulgarians occupy the land for the last four harvests, but rarely mix with the outsiders, says a resident who gave her name just as Magdalena. Most migrant workers lodge in town apartments or buildings supplied by farmers.

"I guess they don't bother us, but I don't like it either," she said. "It's obvious that not all have come to work."

That fear of immigrant crime is one replayed across Europe. In Britain, police bosses have asked for more funds to cope with a dramatic rise in arrivals from eastern Europe: last December Italians torched tents prepared for a new gypsy camp in a Milan suburb.

Farmers in the area have other worries. They complain local authorities take up to two months to register workers, yet the immigrants they depend on to harvest 80 percent of the crop turn up just days before the start of the short picking season.

That means many of the 3,000-4,000 immigrants who work on the local harvest do so illegally, including Romanians and Bulgarians who have no automatic right to work in 13 of the EU's 15 old member states. Madrid has said it will consider opening its market to the new EU entrants from next year.

For Jacinto Trillo, a winegrower and president of a local wine cooperative, the rules are a serious headache.

Growers have to cross their fingers and hope the authorities -- recognizing how important wine-growing is for the region -- turn a blind eye to their illegal employment of non-registered Romanians, Bulgarians and others from outside the EU, he said.

If not, they could be fined up to 6,000 euros for each illegal worker.

An unwelcome spotlight fell on the issue last month when, in the space of a week, three workers without valid contracts died of heart or lung problems in the fields around Socuellamos.

Trillo has had enough. Next year he is going to train his ground-hugging vines onto trellises so they can be mechanically harvested, cutting the migrant workforce on his private vineyard from 10 to zero.