Reuters / The largest U.S. farm group is throwing its weight behind a new immigration law reform that would allow undocumented workers already in the country to gain legal status.

Delegates at the annual meeting of the six-million-member American Farm Bureau Federation issued the call after U.S. Agriculture Secretary Tom Vilsack asked them to speak up for comprehensive immigration reform.

Agriculture has a direct stake in the issue, given its need for a steady and reliable supply of labour to stop certain crops from rotting in the field.

“The reality is we’re only going to solve this through comprehensive immigration reform,” said Bob Stallman, the group’s president.

Immigration reform became a front-burner issue after overwhelming support from Hispanic voters figured in President Barack Obama’s re-election.

The U.S. agricultural industry employs 1.5 million workers annually in temporary or full-time jobs. Many of them, perhaps 500,000 to 900,000 in all, are believed to be undocumented.

Despite the high unemployment rate, farmers and ranchers say it is a perennial struggle to find enough workers to perform the back-breaking labour of fruit and vegetable harvesting, or the daily care of livestock.