(CNN) -- Funny man Stephen Colbert injected a little sarcasm into the congressional record Friday as he testified about farm labor and immigration.

"As we've heard this morning, America's farms are presently far too dependent on immigrant labor to pick our fruits and vegetables," Colbert said in his prepared remarks. "Now the obvious answer is for all of us to stop eating fruits and vegetables. And if you look at the recent obesity statistics, you'll see that many Americans have already started."

Colbert, fresh off Thursday night's "The Colbert Report" episode showing him packing corn and picking beans on a farm as part of a challenge from a pro-immigrant-labor group, is to appear before a House subcommittee on immigration.

He related his experience from the "Take Our Jobs" campaign to committee members.

He didn't answer any questions as he entered the chamber, but tweeted, "There's no good emoticon for testifying before Congress. This'll have to do: [8^($) The $ represents the value of the truth I'll be spewing."

Colbert appeared alongside United Farm Workers President Arturo Rodriguez, whose group over the summer launched "Take Our Jobs," a campaign that challenged U.S. citizens to replace immigrants in farm work.

The group, which says only seven citizens or legal residents have taken it up on the offer, argues that immigrant workers aren't taking citizens' jobs, and is pushing for a bill that would give undocumented farm workers currently in the United States the right to earn legal status.

Pedro Ribeiro, a spokesman for the panel's chairwoman, Democratic Rep. Zoe Lofgren of California, said ahead of the hearing that he didn't know how much in character -- the hyper-patriotic, mock-conservative talk show host that he plays on TV -- Colbert would be. According to The Daily Caller website, Colbert would appear before Congress in character.

"I don't think its a stunt," Lofgren said. "Celebrities add pizzazz to an issue."

On his show Thursday night, Colbert mocked those who deride his appearance, saying he agreed that showing up in character would "sully the good name of experts that Republican-controlled Congresses have actually called to testify in the past," like Elmo, the Sesame Street character who promoted music education before a House subcommittee in 2002.

Ribeiro said the Colbert's appearance in Washington was precipitated by his day on the upstate New York farm, which Lofgren also visited.

"It stems from [Colbert and Lofgren] having worked together on the farm for a day," Ribeiro said.

Phil B. Glaize, chairman of the U.S. Apple Association, and Carol M. Swain, a Vanderbilt University professor, also testified at the hearing.

A Republican on the subcommittee, Rep. Jason Chaffetz of Utah, didn't seem impressed Thursday that Colbert was called to testify. On his Twitter account, Chaffetz said: "What a joke. All the serious issues and we have Colbert as an 'expert.' I am a fan of Colbert, but immigration expert???"

A House Democratic aide, meanwhile, told CNN that House Democrats were buzzing about Colbert's appearance, saying that although he is a comedian, his testimony would be a good way to get attention on the issue.

Colbert explored the issue in July, when Rodriguez came on his show to discuss the "Take Our Jobs" campaign. When Rodriguez told him only three citizens signed up to work on a farm, Colbert told him he'd be the fourth.

The intersection between comedy and politics is nothing new for Colbert, who frequently interviews politicians and commentators.

Colbert this week aired two episodes on his visit to the farm in Hurley, New York, the first of which showed him interviewing Lofgren. When talking about migrant farm workers, she said the United States has two types of signs at the border -- one that says, "No trespassing," and another that says, "Help wanted."

Playing his role as a host with exaggerated conservative views, Colbert responded, "Just take down the help wanted sign. Problem solved. We could get a lot of people in America back to work."

Colbert, along with Comedy Central cohort Jon Stewart of "The Daily Show," also is involved in a send-up of conservative talk show host Glenn Beck's "Restoring America Rally" on Washington's National Mall.

Beck's August rally urged large crowds to "turn back to God" and return America to its founding values. Stewart responded by planning a "Rally to Restore Sanity" for October 30 in Washington. Colbert is countering Stewart with a "March to Keep Fear Alive."

Colbert also announced a bid for the presidency in October 2007, saying he would try to get his name on Democratic and Republican primary ballots in his home state of South Carolina. Democrats rejected his bid, and Colbert said the fee to get on the GOP ballot was too expensive, so he backed down.

A source familiar with Colbert's strategy told CNN at the time that he was using the candidacy to promote his home state. Colbert asked supporters to donate money to South Carolina schools.

Colbert was in character on Thursday when he told ABC's "Good Morning America" about his experience at the New York farm.

"I went out there, and I worked 10 hours in the fields. And I had to stop because my doctors told me I had developed a condition known as a blister," Colbert said on the ABC program.

CNN's Deirdre Walsh, Alison Harding and Catherine E. Shoichet contributed to this report.