WASHINGTON — A proposal by Sen. Dianne Feinstein to legalize up to 1.1 million undocumented farmworkers got its first hearing on Capitol Hill on Monday as a Senate committee spent the day examining various aspects of a sweeping immigration-reform bill.

Feinstein, a California Democrat, wrote the farmworker provision in the 844-bill along with Sen. Michael Bennet, D-Colo., and Republican Sens. Orrin Hatch of Utah and Marco Rubio of Florida. Bennet and Rubio are members of the “Gang of Eight” — four Democratic and four GOP senators — which wrote the overall bill unveiled last week.

The Senate Judiciary Committee, where Feinstein is a senior member, is the first congressional panel to study the entire bill. Monday marked the second of at least three hearings by that panel; the third hearing is today. The committee has to approve the bill before it can advance.

Feinstein said the farmworker language aims to help U.S. farmers, who are struggling under a persistent worker shortage, and to create a professional class of skilled agricultural laborers.

U.S. agriculture is close to a “national crisis with respect to retaining this country’s agricultural prowess,” Feinstein said, adding: “Farms cannot farm because they do not have a consistent supply of workers.”

Under her provision, undocumented workers who work at least 100 days or 575 hours over two years would be given an agricultural, or “blue,” card. Feinstein estimated that between 700,000 and 1.1 million farm laborers across the U.S. would be eligible for these cards. About 300,000 to 400,000 of them are thought to live in California. Blue-card holders must work for at least 500 days over five years or 450 days over three years to get permanent residency, or “green,” cards. Green card holders can live and work in the U.S. forever, but can’t vote or hold some government jobs. Before becoming permanent residents, applicants must pay fines of $400 per person, prove they’ve paid all taxes and shouldn’t have committed serious crimes, according to a summary of the overall bill. The provision also calls for replacing the H-2A migrant worker visa with two new programs that would allow workers to stay in the U.S. for up to six years.

Farmers would have to use the E-Verify system — a database used to verify employees’ legal status — but would have four years from the law’s implementation to comply.

Though Democrats and Republicans on the judiciary committee clashed over other proposals in the immigration bill, they didn’t trade rhetorical barbs over the farmworker language.

Arturo Rodriguez, president of United Farm Workers, said there are 2 million people working on farms and ranches across the United States, and about 600,000 of them are U.S. citizens or permanent residents.

Growers urged committee members to ease the chronic shortage of agricultural workers and warned that failure to do so would leave more fruits and vegetables to rot in U.S. fields and deprive American farmers of billions of dollars worth of revenue.

“For many producers this immigration legislation and this debate before us is more important for the survival of their operations than any of the other legislation pending before Congress,” said Charles Conner, head of the National Council of Farmer Cooperatives. “You cannot get Americans to do this work.”

Groups that favor immigration curbs are skeptical of claims of a massive worker shortage and say Congress shouldn’t give “amnesty” to undocumented immigrants.

Roy Beck, president of NumbersUSA, said lawmakers should instead fix bureaucratic problems that make the H-2A migrant-worker visa program cumbersome to use.

H-2A visas, which are valid for limited periods of time, don’t allow applicants to become permanent residents automatically after working in the U.S. for a few years.

Allowing undocumented workers to obtain green cards will eventually hurt the agriculture industry, Beck said. That’s because permanent residents are likely to move on to less-strenuous or better-paying work once they get their green cards, he said.

“We’ve worked for years in favor of making H-2A more reliable, easier to use for farmers,” Beck said. “The program we have now is the right program. It’s seasonal and you go in and out [of the U.S.].”