WASHINGTON — Less than a year after two bribery scandals produced bipartisan calls for Congress to overhaul the way it finances lawmakers’ pet projects, the $436.6 billion military spending bill passed Friday is packed with them.

The bill, which accounts for about half of federal discretionary spending, includes only a small part of the expected costs of next year’s military operations in Iraq. After the fall elections, President Bush is expected to request another supplemental spending measure to pay for the war, just as the administration has for the last three years.

Lawmakers nonetheless found room in the bill to pay for thousands of requests never sought by the Defense Department. These projects, or earmarks, included $2.1 billion for 10 additional C-17 Globemaster III cargo jets, which the Pentagon is trying to discontinue. They are made by Boeing in the home state of Senator Jim Talent, Republican of Missouri, who is locked in a tight race for re-election.

Lawmakers say earmarks can result in contributions to national security as well as to their districts’ economies. The Defense Department complains that such projects divert billions of dollars from programs the Pentagon considers vital. But both sides agree that earmarks’ merits are hard for Congress and the public to assess.

The number of earmarks has tripled over the last 12 years, straining the ability of Congressional staff members to vet each one. The opaque language of spending bills makes it hard for outsiders to know where the money for each project goes. And it is often impossible to know which lawmaker requested a specific project.

The total cost of earmarks is subject to debate. The House Appropriations Committee said the value of the “member projects” in the spending bill this time was $6.7 billion, down from $7.7 billion in the bill approved last year. The Congressional Research Service estimated the total cost of earmarks in last year’s bill at more than $9 billion. Taxpayers for Common Sense, a nonpartisan group, has identified well over 2,000 earmarks in this year’s bill, roughly on par with last year’s.

Among the earmarks identified by Taxpayers for Common Sense were $1.7 million for photon research in upstate New York, care of Senators Hillary Rodham Clinton and Charles E. Schumer, both Democrats, and $1.2 million for prostate cancer research involving DNA, a pet cause of Senator Ted Stevens, Republican of Alaska, who is chairman of the military spending subcommittee and once suffered from the disease.

Lawmakers’ projects have drawn new attention in the past year because they abetted the misdeeds of former Representative Randy Cunningham, a California Republican who accepted bribes in exchange for earmarking money for military contractors, and the lobbyist Jack Abramoff, who bribed lawmakers to insert earmarks into spending bills.

But as lawmakers head home for the fall campaign season, Congress has done little to alter the earmarking process.

“The appetite is undiminished,” said Senator Tom Coburn, Republican of Oklahoma and a frequent critic of earmarks.

Congressional leaders said they were proud of several broader elements of the spending bill related to the war in Iraq. It includes $70 billion as a bridge until the next supplemental spending request. It provides $22.9 billion to replenish and refurbish equipment for the Army and the Marines. And it pays for a 2.2 percent increase in military pay.

In a shift from previous years, no new items were added — “airdropped,” in the parlance of Capitol Hill — in the conference held to reconcile the House and Senate versions of the bill. If the conferees had added items, an internal rule passed by the House earlier this month would have required the sponsors to take responsibility publicly.

That did not stop the conference from adding $2.1 billion to pay for the additional C-17 Globemaster transport planes. Boeing, which makes the planes in Long Beach, Calif., and St. Louis, has lobbied for months to keep the military buying more. The Pentagon asked for a final 8 planes; the House and Senate bills added 4 more; and in closed conference, the leaders of the two appropriations committees decided to add 10, bringing the total to 22. Each costs about $200 million.

Senator Talent heralded the earmark on Friday with a statement declaring, “Senate approves Talent’s request to keep the C-17 line open” for “our highly skilled workers in Missouri.”