House and Senate farm-state Democrats, in a bitter assault on Reagan administration farm policies, urged the president and Congress yesterday to rescue agriculture from what they called a slide into economic depression.

A dozen senators, led by Walter D. Huddleston of Kentucky, the ranking Democrat on the Agriculture Committee, introduced a resolution urging the administration to take "emergency action" to stabilize the farm economy.

On the House side, another dozen members announced formation of a Farm Crisis Group, headed by Reps. Thomas A. Daschle (D-S.D.) and Kent Hance (D-Tex.), which is drafting emergency legislation aimed at propping up farm prices and easing agricultural credit problems.

The farm-state legislators' push for relief coincides with other pressures on the administration and Congress to provide help to the beleaguered housing and savings-and-loan industries, among others.

As the Democrats were taking out after his farm policies, Agriculture Secretary John R. Block, speaking at a luncheon observance of Agriculture Day, conceded that farmers are in trouble. But he defended his program and urged that the administration's economic policies be given time to work.

That line didn't play well on Capitol Hill, however.

"If the administration continues to sit on its hands and recite its unfulfilled promise that relief is just around the corner, legislative action will clearly be in order. Hooverisms are not enough," Huddleston said.

The resolution he and other Democrats introduced yesterday urges President Reagan and Secretary Block to use existing authority to deal with a sagging farm economy that is buffeted by high interest and inflation and the lowest net income since the Depression era of the 1930s, while production booms.

They want payments to farmers who reduce their planting, higher price support loans for grains, a more aggressive export program, deferral of federal loan repayments and a moratorium on foreclosures, and an economic emergency loan program.

"These actions we are proposing will provide immediate, although temporary, relief to American farmers until such time as our overall national economy begins to return to health," Huddleston said at a heavily attended news conference.

The critical Democrats in the House said patience has worn thin, and frustration on the farm is thick enough to cut with a knife. "Agriculture is in a depression, not a recession or a temporary downswing, but a downright bona fide depression," Daschle said.

"It's a full-scale depression," he added. "We are planning legislation out of exasperation that there is no action by the administration . . . .We are frustrated that our bipartisan request for a meeting with the president has been turned down four times by the White House."

The Daschle-Hance group, with tacit approval from Rep. E (Kika) de la Garza (D-Tex.), chairman of the Agriculture Committee, plans to begin drafting farm support legislation next week, Daschle said. He indicated that Republicans will join in their effort.

The latest rejection of a bid by more than 40 farm-state Republicans and Democrats to meet with Reagan came last week from Michael K. Deaver, deputy chief of staff. He wrote Rep. Byron L. Dorgan (D-N.D.) that Reagan was unable to schedule the meeting they have sought repeatedly since January.

"I can't imagine why he won't meet with us to hear our concern about the farm situation," Daschle said. "Since we asked for the meeting, he's had the National Hockey League all-stars and the Clemson University football team in for visits. If he has time for Clemson football, 42 congressmen should merit some kind of attention."