President Carter yesterday vetoed three bills that he described as inflationary, but at the same time asked farmers to keep land out of production next year as a way to support sagging corn prices.

Carter vetoed a meat import bill that he said would have restricted his ability to boost imports in times of domestic shortages, another measure that would have prohibited reductions in U.S. tariffs on textile imports and a third bill that would have provided $400 million in each of the next two years for nurses' training.

He also called for a program for corn producers designed to idle slightly more land than the program in effect last year.

The corn set-aside decision, expected earlier, had set off a sharp debate within the administration because of its potential inflationary effect.

But administration officials said yesterday that, because of another record corn crop and increased world supplies of feed grains, the action would hardly be felt by the consumer.

"It would have no measurable effect on retail food prices," said Howard Hart, the Agriculture Department's chief economist.

He said it would mean a 4 to 5 percent increase in grain prices in the year beginning Oct. 1, 1979, and that over the next two years grain prices would rise by an average of 2.5 percent.

The net effect, according to presidential assistant Stuart E. Eizenstat, would be to bring corn prices up to their 1976-77 levels.

Despite the fact that food prices have been a leading cause of inflation this year, Eizenstat said no one in the administration had recommended going back to full production.

But there was pressure to enlarge last year's feed grain set-aside program, especially because of the huge crops being harvested while the decision was under consideration.

Alfred Kahn, Carter's new anti-inflation czar, indicated earlier in the week that would fight any moves in that direction.

Yesterday's announcement had been held up partly to await Thursday's crop production forecasts, which showed that farmers will harvest 6.89 billion bushels of corn this year. The September estimate was 6.82 billion bushels, while last year's production was 6.37 billion bushels.

Carter tried to head off criticism of the acreage set-aside decision by coupling it with the three veto messages. The four actions, he said, "underscore my commitment to restraining inflation and to implementing an anti-inflation program which is fair but tough."

The White House said yesterday that Carter has now vetoed 19 bills since taking office, 17 of them this year, and 13 of those were pocket vetoes, meaning the president let the bills die without positive action on his part.

Eizenstat said Carter had been "judicious" in his use of veto, but warned that the president is ready to use it more in the future to keep spending down.

At the same time, Eizenstat defended Carter's decision to sign a veterans' benefit bill last week - without fanfare - that critics said would add several billion dollars to the budget deficit, Eizenstat said that bill contained important reforms that would bring sizable savings, and termed opponents' literature on the bill "misleading."

Of the three vetoed bills, the textile measure was seen by administration officials as potentially the most damaging. "We are attempting to negotiate mutual reductions of tariffs and non-tariff barriers to trade around the world," Carter said in his message.

"By completely exempting an entire industry from these negotiations, we risk a series of retaliatory actions by our trading partners on those agricultural and industrial products which have the greatest potential for increased U.S. exports," he said.

Carter also said the action could lead to the collapse of the talks, which he termed "vital" to relieving inflationary pressures here and abroad.

But the president of the American Textile Manufacturers, Robert S. Small, called the veto a "grave disappointment" to an industry "already suffering severe injury with existing tariffs."

U.S. cattlemen were no happier about Carter's veto of the meat import bill. The president said he had taken the action despite several features of the bill that he said improved the existing meat import program.

He said the new measure contained such severe restrictions on his authority to boost meat imports during periods of shortage that he could not accept it.He also objected to the 1.2 billion-pound limit on imports imposed by the bill. The administration had favored 1.3 billion pounds.

Richard A. McDougal, president of the National Cattlemen's Association said the bill was actually anti-inflationary and that Carter's veto was based "more on short-term political expediency than on long-term good." He predicted that it would mean higher beef prices through the early 1980s.

Eizenstat said Carter had vetoed the nurses' training bill because it would have locked the administration into funding level for fiscal year 1980. The administration is looking for places to cut the fiscal 1980 budget, in line with Carter's strict orders to keep the deficit at no more than $30 billion.

The nurses' training bill also contained emergency funding for three black medical schools, which had said they would be forced to close without additional money.