Farm-state legislators, fuming over an unusual White House attempt to force them to sign a "contract" pledging support of President Reagan's planned farm bill, wrangled with the administration yesterday over the terms of an emergency farm-credit package.

Office of Management and Budget Director David A. Stockman and Agriculture Secretary John R. Block met again in private with senators, who indicated that there was progress but that the administration's proposals amounted to not much more than a "Band-Aid."

The political furor over the developing Farm Belt credit crunch was fueled by a document Stockman delivered Thursday to Republican senators.

The document was a formal "contract" in which the administration would trade help on credit now for a Senate promise to support forthcoming farm legislation that would cut back many programs valued by Congress.

Stockman's approach, which went well beyond customary congressional deal-cutting, left the legislators seething.

Republicans and Democrats took equal offense at the unorthodox "contract," and the proposal was "torpedoed," Sen. J. James Exon (D-Neb.) said, because farm-state legislators are insisting that the credit crisis must be dealt with on its own.

Senate Majority Leader Robert J. Dole (R-Kan.) expressed a common view. "I don't sign contracts," he said, but added that Stockman is "just trying to keep us honest."

Despite the wrangling, Block called yesterday's session "excellent" and promised that "some help will be coming," although he provided no details. The hurried round of meetings yesterday and Thursday came after repeated administration denials that any changes were contemplated in President Reagan's existing farm-credit program.

Reagan's plan, announced six weeks before the November election, provided federal guarantees for private bank loans to farmers and liberalized loan-repayment provisions for Farmers Home Administration borrowers. Most experts agree that neither part of the package has worked.

Sources indicated that a final package likely will be announced next week.

Pressure for help from Washington has intensified in recent days, with farm groups, bankers and legislators warning that thousands of farmers could be put out of business and small country banks ruined if the administration does not respond quickly.

Most senators applauded the administration's latest moves, but a number of them worried out loud that the help would come too late to avert a rash of foreclosures in the next several months as farmers find they cannot get loans for spring planting.

Dole, for example, said the White House offer represents "a Band-Aid, not a solution," although he conceded that it might help many credit-strapped farmers.

Sen. Edward Zorinsky (Neb.), one of several Democrats invited to yesterday's meeting, said the credit program was a step forward but that it would not be enough to save many deserving farmers from foreclosure.

Stockman's contract offer, however, offended legislators in a bipartisan way.

Rep. Pat Roberts (R-Kan.), after hearing the contract offer at a briefing Thursday night, said, "I found them personally insulting . . . . I'm extremely disappointed in how they approached this thing."

Sen. Tom Harkin (D-Iowa), one of those allowed into yesterday's session, said "I think this is the most reprehensible form of blackmail we can have in our society."

He added, "This crisis is not going to go away with the kind of Band-Aid and pablum we're getting from David Stockman."

According to senators and staffers in the meeting, the OMB director stirred more emotion by saying that farmers, as well as other "special interests," were going to be "cut off at the knees" by the administration's effort to reduce federal spending in the fiscal 1986 budget that will go to Congress next week.

There were these other developments yesterday on farm credit:

* Sens. Exon and David L. Boren (D-Okla.) notified Dole by letter that when the Senate returns from recess this month, they will introduce a "major" farm-credit bill and then stop consideration of any other issue on the Senate floor until they get action on their proposal.

* Rep. E (Kika) de la Garza (D-Tex.), chairman of the House Agriculture Committee, announced that a credit subcommittee will hold a hearing Feb. 7 to hear proposals for legislative remedies to deal with the farm economic crunch.