The farm credit crisis reached the Cabinet discussion level yesterday, but a White House spokesman said President Reagan has no new proposals under consideration for easing the plight of farmers facing the possibility of not obtaining loans for spring planting.

The administration has come under increasing pressure in recent weeks, from Republicans as well as Democrats in the Farm Belt, to move quickly on a series of remedies for the credit squeeze facing thousands of farmers and country banks.

"We view it as a significant serious economic situation that needs to be focused on," deputy White House press secretary Marlin Fitzwater said yesterday. But he said Reagan is not considering any new approaches beyond the debt restructuring he announced last fall.

"We're just monitoring the situation," Fitzwater said. "It's a difficult problem. We don't have any new proposals."

According to reports, the Cabinet devoted most of yesterday's meeting to a discussion of the farm situation, as did the Cabinet Council on Economic Affairs earlier in the day.

Although the White House was announcing no new moves and didn't indicate that it intended to make any, Sen. Charles E. Grassley (R-Iowa) launched another broadside naming Office of Management and Budget director David A. Stockman as a chief villain in the administration's go-slow approach.

Grassley, whose state's farm economy is reeling under high interest rates, low commodity prices and falling land values, said, "It is time for our administration to put its money where its mouth was in September when it announced the debt restructuring program."

He charged in effect that Stockman is carrying out a vendetta against farmers and rural America either because "he really doesn't care" or because he sees the current credit crunch as a way of hastening adoption of the "free-market" agriculture that the administration supports.

"David Stockman even opposed the September debt restructuring program announced by the president," Grassley said yesterday. "I can't believe that Stockman doesn't already know what the situation is. His unwillingness to take action is an indication that he really doesn't care . . . .

"There is a lack of understanding . . . . I don't see David Stockman jumping on Defense Secretary Caspar Weinberger," Grassley added. "Just eliminating the subsidy in the defense budget would deal with the deficit. The president is my hope. My hope is that he'll overrule David Stockman."

Grassley repeated a call that he and Sens. Robert J. Dole (R-Kan.) and David F. Durenberger (R-Minn.) made to the president on Monday, urging that the administration broaden the debt assistance announced by Reagan six weeks before last November's election.

Their letter to Reagan said "the fact that only $25 million of the $630 million in federal loan guarantees made available in your program has actually been allocated provides ample testimony that relief targeted for farmers has somehow been held hostage in the system."

They and other farm state legislators are pushing for changes that would allow banks to reduce interest rates as well as principal on guaranteed loans, to expand loan guarantees beyond the authorized $630 million, to add more personnel to overworked Farmers Home Administration offices to handle a flood of relief applications, and broaden the rules to let more farmers in.

On another front yesterday, leaders of five farm organizations and about 100 farmers from around the country fanned out across the capital to try to persuade officials of the urgency of reducing the federal budget deficit -- a move they said would help the sagging farm export market and would lower interest rates that farmers must pay for operating loans.

Roger Asendorf, president of the American Soybean Association, said net farm income would be raised by $10 billion if the prime lending rate were cut to 8 percent. The Agriculture Department reports that farm income last year ranged between $29 billion and $33 billion.

The farm groups, calling themselves the Balanced Budget Brigade, brought more than 1 million cards addressed to the president and members of Congress in support of a balanced budget.