Although the economy will dominate the early going, the Republicans who will control the Senate and wield increased power in the House this year will have a chance to strut their stuff on a lot of other issues, too.

It is an accident of the legislative calendar, but many programs the Republicans don't like, or at any rate have pledged to cut, come up for renewal in 1981. The 97th Congress will be a lively one.

What, for example, will this demonstrably more conservative Congress do about a dairy price-support program that could cost taxpayers $1.4 billion in 1981? It comes up for renewal in the farm bill.

How will the elected economizers deal with the Reagan transportation task force recommendation that the popular interstate highway building program be put in a deep freeze?

And how, in the face of continuing public support for clean air, will it deal with proposals to modify substantially the expiring air pollution control laws in the name of less regulation and less expense?

What about cancer-causing additives in food? Energy development programs? Nuclear-plant licensing and siting? Job safety? Nuclear waste disposal? Oil spills? They will come up, too.

President-elect Ronald Reagan and his transition advisers have made their views known on many of these issues, but as another new president had to discover four short years ago, federal programs and policies are finally hammered out not in presidential speeches but congressional committee rooms.

One of the busiest anvils well could be that of the Senate Environment and Public Works Committee, which has a new chairman, moderate Robert T. Stafford (R-Vt.), and a raft of new members unfamiliar with old programs that will be up for revision.

The main priority will be the Clean Air Act, which is expected to undergo intense debate and modification, highlighted by the new administrations contention that relaxation of power-plant and automobile pollution standards could save industry billions of dollars.

Stafford's committee also must deal with the Clean Water Act, which, although not expiring until 1982, will be on the agenda because waste-treatment grant authorizations are due for renewal this year. Endangered species; the highway act, which provides for the interstates and other federal road-support; oil-spill protection; Economic Development Administration and Nuclear Regulatory Commission extensions also are on the docket.

Another major topic of controversy and hyperactivity could be agriculture, with the basic farm program that covers issues from price supports and food stamps to export policy due for renewal.

The focus will likely be on the Senate Agriculture Committee, whose new chairman, conservative Jesse Helms (R-N.C.) is widely known as an acerbic critic of the growing costs of federally supported nutrition programs.

Helms' chief adviser, George Dunlop, acknowledged that the fight over food stamps is likely to be bitter. But he said that Helms does not intend to "ram anything down anyone's throat" and "will try to get the votes he needs in a reasonable way."

The critics of federal regulation will get a chance in the House and Senate Commerce committees to take on the Consumer Product Safety Commission, whose authorizing act expires and heated debate is expectd when the Reagan administration makes its promised moves against regulations of the Occupational Safety and Health Administration.

James Delaney, the former congressman from New York, is gone but his legacy and the bitter debate it provoked linger on. The so-called Delaney Amendment, which bans as food additives any agents that cause cancer in laboratory animals, is expected to be under new attack as the Saccharin Study and Labeling Act expires July 30. Saccharin use is now permitted in an exception to the Delaney Amendment.

A vehicle for the guerrillas of the Sagebrush Rebellion, angry over federal control of much of the land in the West, may be the Federal Land Policy and Management Act, which will be open to debate and change. Rep. Jim Santini (D-Nev.) and others already are brandishing bills that would transfer federal lands to the states.

Other major federal programs with 1981 expirations, all of which can be expected to produce heated discussion and probable change, include Amtrak passenger train operations; Head Start and vocational education; home-energy assistance; hazardous liquid and natural gas pipeline safety; flood insurance, and some refugee assistance activities.

As if that were not enough for a new and rambunctious Congress, there is a goodly ration of leftovers from the 96th Congress -- issue left stranded by the trap of time, lobbying and disagreement.

For instance, the Department of Energy that everyone rails about and which candidate Reagan promised to do something about (abolish) will be back before Congress seeking an authorization -- a nicety it has not had to entertain since its creation in 1977. In the disputatious interim, departmental policy largely has been set by the Appropriations committees.

Rep. Morris K. Udal (D-Ariz.), House Interior chairman, already is girding for energy-related struggles in his committee, all from that same platter of leftovers; streamlining of nuclear plant licensing procedure, coal, slurry pipeline authorization, fasttrack treatment of energy-environment disputes, a program for long-term storage of high-level radioactive nuclear waste.

The struggles are likely to be intensified by another key element in the makeup of the new Congress -- split party control of the two chambers. Udall's Senate counterpart will be James A. McClure (R-Idaho), who rarely agrees with him on anything but the time of day.

Republicans will have another opportunity to put performance where their platform stands when debate resumes over the 55-mph speed limit. The GOP wants it abolished.

The GOP campaign emphasis on strengthening intelligence-gathering capabilities could find fruit in the new legislature, as well. Congressional Democrats and President Carter never could find common ground for defining the limits and tasks of the sleuths and spies. A new push is expected for approval of charters for the intelligence organizations.

And those who like to point out the connections between campaign ties and performance in office will keep a gleeful eye peeled on such other leftover issues as maritime subsidies and a relaxation of interstate highway load limits.

The Teamsters, the largest union to support Reagan's candidacy, want larger trucks permitted on the super-highways. The 96th Congress didn't authorize new weight limits. The only other major union supporting Reagan, the National Maritime Union, has a keen interest in revival of an omnibus maritime shipbuilding and subsidy bill that stalled last year.