President Barack Obama's executive action preventing the deportation of some 5 million illegal immigrants could cause a significant labor shortage for Californian farmers.

"This action isn't going to bring new workers to agriculture," said Jason Resnick, vice president and general counsel of the Western Growers trade association, The Associated Press reported.

That's because under Obama's new immigration plan, many of those farmworkers will be shielded from deportation, receive work permits, and could end up leaving their unstable seasonal farm jobs for more secure year-round work.

According to Manuel Cunha, president of the Fresno-based Nisei Farmer League, 85 percent of California's agricultural workers currently use false documents to obtain work, the AP reported.

Cunha said he believes that 50,000 of California's 330,000 farmworkers could end up leaving the state's $46.4 billion industry because of immigration policy.

While most farmworkers make more than minimum wage and even earn more per hour than they would in other industries, Cunha said that many workers will leave the farm for a year-round job with regular paychecks, rather than continuing with seasonal farm work.

"It's possible that because of this action, agriculture will lose workers without any mechanism to bring in new workers," Resnick added, estimating that there is already a 15 to 20 percent shortage of farmworkers.

The agricultural industry largely believes that Congress needs to enact comprehensive immigration reform which includes an effective guest worker program, according to the AP.

"That's the right thing to do for this country," according to Karen Ross, secretary of the California Department of Food and Agriculture.

On the other hand, Ed Kissam, an immigration researcher at the immigrant advocacy group WKF Giving Fund, told the AP he doesn't believe a significant number of farmworkers will leave the industry because they don't have the language skills, education or technical abilities to obtain better employment.