PESCADERO — The handful of laborers harvesting leeks in farmer Joe Muzzi's field are all that's left of the seasonal work force he depends on to tend to his crops every year.

Twenty other men have gone home to Mexico, as usual, for the winter. This time, however, they left Muzzi wondering how many would return this spring.

"The thing that we're worried about is, 'Will they be able to come back?'" said Muzzi.

As the land prepares to hibernate, other Coastside farmers are wondering the same thing: What a stepped-up border patrol and a new set of passport requirements for the U.S.-Mexico border will mean for their work force come springtime. Existing labor shortages already forced Muzzi to cut back 15 percent of his crops this year.

And he isn't alone. Local undocumented migrant workers take a gamble every year as they cross back into Mexico to visit the families they support by working in the fields and flower nurseries of San Mateo County. As border enforcement tightens on the ground, a new Department of Homeland Security requirement to present a passport to board flights into the United States may present more complications for field workers on their way back to a guaranteed job in this country.

"These are people who come back year after year because they have good jobs and a community here," said Kerry Lobel, interim executive director of Puente de la Costa Sur, a migrant worker resource center in Pescadero.

"Their family depends on them," she added. "It's not like going to visit your grandmother for Thanksgiving. If you can't get back, your family's going to starve."

The stakes are high for farmers, too. Muzzi estimated that 75 percent of his peak work force of 50 men is composed of seasonal workers; 25 percent of those workers are new faces every year. Muzzi said he was prepared to cut his crops back another 15 percent this year if necessary.

"Last year we were five or six men short, but this year we'll be 10 or 15," said Muzzi. He also is looking into the possibility of buying a machine to harvest his Brussels sprouts in place of human labor.

Statewide, the agriculture industry has become heavily dependent on seasonal workers. The total number of these workers sprouted from 136,000 in 1974 to more than 201,000 in 2002, an increase of 48 percent, according to the National Agricultural Statistics Service. In a survey for the year 2003-2004 by the National Agricultural Workers Survey for California, only 20 percent of field workers said they worked for their employer year-round.

For years, B.J. Burns has hired 10 workers a year to help him plant, maintain and harvest his cut flowers and pumpkins at Bianchi Farms in Pescadero. Seven of those workers have returned home for the winter. Short-handed during the peak harvest this past summer, Burns said he had to borrow a few part-time workers from the local nurseries.

"We have no source of work force other than the ones who are coming here," said Burns, sitting in his office. "I don't know what's going to happen. I've just got a feeling we're going to lose workers in'07," he said. "That means you're either going to cut your crops back or lose them."

Fewer workers also means more competition for laborers across the spectrum. Muzzi pays his workers an hourly wage of $7.50 to $10.50 with free housing, but says he can't compete with salaries of up to $15 an hour offered to workers on construction projects.

"If we get to the point where we're planting less and less, we get to the point where we don't attract labor. Nowadays, you have to pay top dollar and have work there every day," said Muzzi. "And if we have to cut back, the consumer will be paying more."

Carlos Ponce, 23, has worked in the fields of Pescadero for two years without returning to his home state of Jalisco to visit his parents and five brothers and sisters. He said he intends to visit them next December. Until then, he'll continue working in town.

"I'm staying to make money," said Ponce, taking a break from work in leek-stained yellow overalls. "It's really hard to come back. Sometimes the coyotes don't want certain people to come," he said, referring to the people who smuggle undocumented workers into the states.

Pescadero is pretty quiet these days. Few laborers are seen riding their bicycles through town or standing in front of the taqueria together as they do in summertime.

Lobel wonders how many of them will reappear.

"People are going where there's jobs and housing and where there's more perceived access to community life," she said.

Meanwhile, Puente de la Costa Sur has been altering its outreach to support an emerging population of workers and their families who have chosen to stay in Pescadero over the long term to avoid the risk of losing their housing or employment.

"We're seeing fewer people coming to town and needing our welcome bags and our bikes," said Lobel. "The number of times people come to see us in a year is increasing. They're here longer and their needs are for a place to be rooted, for mental and physical health services."

Local farmers aren't the only ones who suffer when the migrant workers, who double Pescadero's population of 1,500 in the summer, are absent. The town's gas station, taqueria and only grocery store are dependent on them, too.

"The truth is, we need the Mexicans here in town," said Catherine Peery, chair of the Pescadero Municipal Advisory Council. "Children of farm workers make up 60 percent or more of our school district's population. Without them we wouldn't have a school, and without a school, we wouldn't have a town."

As more Coastside farmers cut back their operations, Lobel predicted that agricultural laborers would eventually have no choice but to choose large-scale productions over operations like Muzzi's.

"In the short term, there's a labor shortage, but in the long term, family farms that are hiring workers are not sustainable. That's the majority of the farms in Pescadero," said Lobel. "It will be a different place when that whole part of our social fabric is gone."

Staff writer Julia Scott can be reached at (650) 348-4340 or at jscott@angnewspapers.com.