Richard E. Lyng, who became secretary of agriculture with a reputation as a political past master, has stirred up a first-class political tempest after only a week on the job.

Lyng came under bipartisan attack on Capitol Hill yesterday for his decision to pay for an Agriculture Department program in Florida by canceling an $11 million soil research laboratory project in Iowa.

The decision took on political overtones when Sen. Paula Hawkins (R-Fla.), facing a tight reelection race, and two GOP House members from Florida announced the windfall in a news conference televised from the Agriculture Department after they met with Lyng Thursday.

Aides to Lyng roiled the waters more by telling AgriData News Service that the "emergency" funding was provided at Hawkins' request to help her reelection campaign.

Iowans reacted bitterly to Lyng's plan to cancel the National Soil Tilth Laboratory, which was to be built on the Iowa State University at Ames, and accused the secretary of playing politics. Iowa legislators were not informed in advance of the secretary's fund switch.

Sen. Charles E. Grassley (R-Iowa), a reelection candidate who often is at odds with the Reagan administration over farm policy, told aides that the decision was "stupid" and that it "astounded" other GOP senators.

Sen. Tom Harkin (D-Iowa) said the laboratory was of "vital importance" to Iowa. "The preservation of our soil is too important to jeopardize for short-term political gain. Both Republicans and Democrats have objections to this questionable action."

Rep. Jamie L. Whitten (D-Miss.), chairman of the House Appropriations Committee, went a step further. At a hastily called meeting of his agriculture subcommittee, Whitten told Lyng yesterday that the decision violated a law that bars such fund transfers without congressional authorization.

"It is political when you cancel a laboratory approved by Congress," Whitten said afterward. "I agree that Florida needs the money and I have introduced a bill that will provide it. In season and out of season, we've worked with the department. We can do better if we talk beforehand about these things."

"I hate to see you get off on this foot," Whitten told Lyng.

Rep. Virginia Smith (R-Neb.) said she also was unhappy with the decision to cancel the laboratory, which she said would provide important benefits to Nebraska farmers.

Lyng told the subcommittee that he acted on the advice of USDA lawyers, but said that if he had been misinformed "we will fix it."

The $11 million ticketed for Florida was due as the federal share of a federal-state citrus canker disease eradication program that reimburses nurserymen who are forced to destroy citrus stock.

A political end note: The soil research laboratory was a pet project of former Iowa senator Roger Jepsen, a Republican.