Piqued by years of Reagan administration efforts to cut soil-conservation spending, the House Appropriations Committee has retaliated by eliminating the job of George S. Dunlop, the assistant secretary of agriculture who oversees the programs.

And, for good measure, the committee cut in half the fiscal 1988 budget of the office of Vance L. Clark, head of the Farmers Home Administration (FmHA), on the theory that if he won't do his job as the panel sees it, he doesn't need the money.

This back-and-forth has become a yearly exercise between the department and the committee, which is chaired by Rep. Jamie L. Whitten (D-Miss.), who does not mind expressing his definite ideas about how the Agriculture Department should function. The department and Whitten have been at odds since 1981 over conservation and FmHA programs.

But the odds have never been quite so bluntly expressed as this time.

Under Whitten's direction, the committee restored $456.7 million in soil conservation funds that the White House wanted killed, and it refused to go along with the $3.2 billion in cuts sought on FmHA rural development, rural housing and farmers' loan programs.

To frost the cake, the committee then ordered that the account of the assistant secretary for natural resources and environment (Dunlop, that is) be eliminated and that duties of the office be transferred to Secretary Richard E. Lyng.

"After several years of continued rejection by the people and the Congress, the department continues to submit conservation budget proposals that are simply out of touch with the public interest," the committee report said. "Once again, the committee must face the task of restoring funds for the Soil Conservation Service."

Dunlop, a former staff director of the Senate Agriculture Committee and longtime associate of Sen. Jesse Helms (R-N.C.), was taking the slap in stride yesterday. "We have read the report . . . . Mr. Whitten has wanted to get our attention," he said, "and we are the kind of people who want to have our attention gotten. We believe in having good relations with Congress."

Dunlop said that the committee report caught the department off guard and that Deputy Secretary Peter Myers has been delegated to "engage" Whitten in talks to learn more about the chairman's unhappiness with the department.

As for FmHA, the committee said that Clark had shown a "repeated failure" to help farmers and rural residents and that he had ignored congressional intent by setting up policies designed to foreclose on troubled farmers.

The committee also said that Clark's office was overstaffed and ordered the administrator's budget halved to $394,000.

While ordering Clark to spend more money on rural housing, the committee took another swipe at FmHA by ordering the agency's administrative budget in New York state reduced $250,000 below the White House request.

That seeming contradiction was engineered by Rep. Matthew F. McHugh (D-N.Y.), who was angry that the New York arm of FmHA was obligating rural housing loan funds at a rate about 20 percent lower than the national average. McHugh attributed the lag to "foot dragging and poor management . . . . it's time to let the FmHA know that it can't continue to thwart the intent of Congress."

In the end, the committee's harsh treatment of the Agriculture Department could turn out to be more symbolic than real, although the message is unmistakable: Chairman Whitten and his Appropriations colleagues have had it up to here with departmental intransigence.

The Senate Appropriations Committee version of the 1988 spending bill ignored the department's budget proposal and put money back into the FmHA and soil conservation programs. But it also left the budgets of Dunlop and Clark intact, with no criticism.

Assuming that the bills pass the House and Senate without change, the differences in the two measures would become the subject for negotiation in a House-Senate conference. The House could prevail, or not.