Vice President Gore forced Bill Bradley onto the defensive today during their first debate in Iowa, using a farmer planted in the audience to personalize a broad assault on Bradley's agriculture record as a New Jersey senator.

The Jan. 24 caucuses in Iowa, where farming is a key part of the economy, are the first major test in the race for the presidential nomination, and Bradley has sought for months to explain that although he used to view farm issues as a New Jerseyite, he now is committed to helping family farmers.

"Let me introduce a friend to you," Gore said when the moderator gave him a chance to question Bradley, his rival for the Democratic nomination. "Chris Pederson is here. Could you stand up, Chris?" Turning to Bradley, Gore asked, "Why did you vote against the disaster relief for Chris Pederson when he and thousands of other farmers here in Iowa needed it after those '93 floods?"

Bradley appeared taken aback and sought to recover throughout the rest of the hour-long debate, which was broadcast statewide on public television and nationally on several cable networks. "You know, Al, I think the premise of your question is wrong," Bradley said. "This is not about the past. This is about the future. . . . You can talk about the past, but I prefer to talk about the future."

Gore chuckled and said, "Well, I can understand why you don't want to talk about the past. . . . Those floods, they created a great lake on the satellite pictures out here. It was a genuine catastrophe." Gore then pointed to "many other droughts and disasters facing farmers where you were one of a handful who didn't help the farmers."

In an acknowledgment that he is not well-versed in farm issues, Bradley said that just as President Franklin D. Roosevelt chose an Iowan, Henry Wallace, as agriculture secretary, he might choose popular Gov. Tom Vilsack (D), whose wife, Christie, makes frequent appearances for Gore.

Bradley appeared to realize that Gore had scored with the question and used much of his closing statement to affirm his concern for family farmers. "Al's been hammering me on my agriculture votes 15 years ago," he said. "I would simply ask the family farmers of Iowa today, are you better off than you were seven years ago? Or do we need a change?"

Both candidates, mindful of polls that show voters craving civility, avoided the harsh exchanges of some of their past encounters. In Gore's closing statement, he said it was an honor to be in a race with Bradley.

"I don't want any of you all to mistake the heated disagreements that we have about issues as disagreements about the basic character or goodness of the individual," Gore said. "Senator Bradley is a good man, and I've learned a lot during these debates."

The debate was in Johnston, a Des Moines suburb, at Iowa Public Television studios, where the lobby sports human-sized stuffed characters from "Sesame Street." Bradley and Gore stood at lecterns, separated by the moderator, Dennis Ryerson, editor of the Des Moines Register, and before a huge backdrop of tie-dyed muslin, washed in red, white and blue light, with stars and firework effects projected from above.

This morning, the candidates woke up to a banner headline in the Register: "Poll, Gore Checks Bradley." The newspaper's poll found Bradley had made no inroads in Iowa since November. The poll of 501 likely Democratic caucus-goers showed Gore, who has the backing of the state's Democratic establishment, with 54 percent and Bradley with 33 percent, while 7 percent said they were unsure and 6 percent were uncommitted.

Caucus-goers, who must attend a 7 p.m. precinct gathering that can last hours, tend to be intensely political as opposed to the more casual voters who often participate in a primary. The Iowa poll found that 65 percent of likely Democratic caucus-goers said they had watched at least some of the debates.

Bradley used the debate, the Democrats' fifth, to expand his frequent attack on Gore as a Washington insider. In a backhanded criticism of the Clinton-Gore administration's rightward shift from its original goals, Bradley adopted a signature line from Clinton's 1992 campaign. "It used to be popular in politics to say that you were fighting for the people who work and play by the rules," Bradley said. "I'm still fighting for the people who work hard and play by the rules."

Bradley, who has faced sustained criticism from Gore for failing to produce a full-fledged education program, contends that he has included education in a wide range of other proposals, including his plans for health care and poor children. Bradley charged that in contrast, Gore views education "as if it's some bureaucratic box that says 'Education' that's unrelated to everything else we do in our lives."

"I have the perspective of life, and I think the vice president has a perspective that's a box called 'Education,' " Bradley said.

That fit Bradley's strategy of portraying Gore as a bureaucracy-minded politician obsessed with specific programs, while presenting himself as a forward-looking leader who thinks broadly and deeply.

Gore, on the other hand, wanted to zero in on what he believed were Bradley's vulnerabilities in Iowa by sprinkling the debate with what his aides called "an Iowa issues test" that he believed would flummox Bradley. Gore opened the debate by parrying Bradley's charge from the last debate that the vice president has been trapped in a Washington bunker.

"I want to start by telling you what we were doing in that Washington bunker," Gore said. "We've created 20 million new jobs, cut the welfare rolls in half, passed the toughest gun control in a generation, and created the strongest economy in the history of the United States of America."

"That's not a bunker," Gore continued. "Those are the front lines in the fight for our future."

Reprising a challenge from the last debate, Gore said he would stop advertising in any state of Bradley's choice if his opponent also left the airwaves and agreed to twice-weekly debates. Bradley, who has contended that would hurt him more because fewer people know him, again refused.

"In 30 seconds, you can say a lot," Bradley lectured in defense of television commercials. "I'm for a woman's right to choose, I'm for affordable health care accessible to all Americans. I'm for education improvement in this country, I'm for trying to make sure campaign finance reform is a reality, that working families have a better chance to advance, and that we eliminate child poverty. . . . How's that?"

Responding to questions about international trade and security, Bradley defended his willingness to increase the role of the United Nations and the World Trade Organization. He said the United States should not continue to try to be "the policeman to the world. . . . That means we're going to have to move more and more to multilateral forums."

Gore appeared more willing to back the use of military force for peacekeeping, but he said the nation must have a national security interest at stake and assurances that force would "solve the problem."

CAPTION: Democratic presidential candidates Bill Bradley, left, and Vice President Gore in exchange from first Iowa debate.