-- The work is grueling, the pay meager, and home might be a crowded bunkhouse or the back of a van, but migrant families in southern New Jersey for the blueberry harvest receive a perk worthy of their labors.

Their children, whether toddlers or teenagers, qualify for a free, state-of-the-art summer school, with multilingual teachers encouraging pupils they might never see again after berry season. While the parents toil in the fields, their sons and daughters might be exploring the Internet or practicing with a precision drill team.

Many of the families swiftly move on, heading to late-summer jobs in Maine or Michigan, then returning to Mexico or Florida for the winter before starting a northward trek again in the spring -- their children experiencing school in short, disrupted spurts. Summer school -- part of an imperfect but ambitious federal initiative -- is intended to fill the gaps and keep the children within academic striking distance of their more stable peers.

The challenges are numerous. Many of the children speak little English, and they come from a hodgepodge of cultures and disjointed educational backgrounds. Older children may prefer to be earning money in the fields. And the staff knows it has only six weeks to work with.

The Sicklerville program accommodates children as young as 3. A separate Migrant Head Start Program accepts children as young as 6 months. "Our staff needs to be realistic -- they may have just one shot at these kids," said Peg Cunningham, co-director of a New Jersey-based Head Start program.

"One of the biggest challenges for the teachers is not having the satisfaction of seeing the long-term benefits of their work," said Kathy Freudenberg, director of a nine-county New Jersey summer program that serves about 1,000 migrant children.

There are an estimated 860,000 school-age children of migrant workers in the United States -- mostly Hispanic -- with about 550,000 of them receiving some form of federally subsidized education. A $380 million budget covers both school-year and summer programs, which are administered by the states and considered vital in helping the children finish high school.

Alma Ramirez, 14, is among those intent on graduating. Along with her parents and three siblings, she came to New Jersey two years ago from a village in Mexico's Hidalgo state. She finished ninth grade in Clayton, N.J., this spring, and now -- while her father works in a nursery -- she is at summer school.

While she has learned English quickly, the language barrier has left Alma feeling a little isolated at her regular school. The summer program is a pleasant break. There are just one or two children at her regular school who speak Spanish, she said. "But here, I have a lot of friends who do."

Other migrant children also appreciate the chance not to be outsiders for once -- and to avoid the teasing they often suffer at mainstream schools.

Alma's summer program is based at a large elementary school in Sicklerville, halfway between Philadelphia and Atlantic City in the heart of New Jersey's blueberry country. About 200 children are picked up from field-side camps and run-down motels by a fleet of buses, brought to school in time for breakfast, then taken after classes to a summer camp for recreation and supper before heading back to their families.

Most of the families are from Mexico, others from Haiti. Many of the children were born in American farming towns and are U.S. citizens. "The Haitian and Mexican kids are very distant -- they don't know each other's culture," Freudenberg said. "We try to promote harmony."

To woo teenagers into class, the school offers some part-time jobs where students can earn $6 an hour doing tasks such as cleaning the cafeteria. Juan Carlos Castenada, a 14-year-old who has such a job, said the summer school is much bigger and better equipped than his three-classroom school in Mexico.

But daily life can be tough. Haitian-born Wesley Jarbath, 15, came to New Jersey from Florida with his sister and grandmother, who works in a berry-packing house. He lives apart from them in a men-only bunkhouse, attending summer school while the men work. Most of the children can expect little hands-on help at home. But staff members say most parents support the summer program and flock to the annual Parents Night.

"Education is a key reason a lot of these families came to America -- they want something better for their kids," Freudenberg said. "The kids really want to be in summer school."

The program's chief recruiter is Andrea Hutchinson, who was raised in a migrant-worker family in California. She sets out by car each afternoon, tracking down families at the end of dirt farm roads to register their children.

Most of the parents are delighted to sign up their younger children, but many of the children 12 and older -- legally able to pick berries for pay -- choose work over school. Evening English classes are offered for them.

Hutchinson said farm owners generally cooperate because they can face federal fines if young children are spotted around the fields. But they can make other aspects of migrant life harsh, she said.

"The rent is high -- there's a lot of exploitation," Hutchinson said, citing such practices as requiring migrant families who live on farm property to buy meals onsite rather than allowing them to cook for themselves.

At the Cosmo blueberry farm in the town of Atco, Hutchinson and two colleagues signed up several children of newly arrived migrants. Parents who spoke no English provided ages and health information as small children milled about a muddy parking area adjoining a cluster of trailers and bunkhouses.

One of the difficulties of migrant education is tracking students as they move. One attempt at a nationwide data bank collapsed several years ago. The federal Office of Migrant Education, led by Francisco Garcia, is now making a new attempt to link up existing state information systems so a school in one state could swiftly access students' test scores, class credits and immunization records from another state.

Garcia, who has worked in migrant education since 1965, said he has witnessed tremendous change since a time when many school districts balked at serving migrants' children.

"We still run into some resistance," he said. "But, for the most part, they've been receptive. They want to do their best to put everyone on the same playing field."

While their parents toil in New Jersey blueberry fields, children of migrant workers attend summer school made possible through a federal program. Dentist Melvin K. Pierson and his assistant, Mayra Ramos, examine the teeth of Jocelyn Rivera, 12.Laydee Velasquez, 3, enjoys a coloring book. The school serves children as young as 3.