WASHINGTON — The Senate on Thursday sealed a veto-proof majority in Congress for the next five-year farm bill, making President Bush's vow to veto it a mere formality on its way to becoming law.

"It doesn't make sense to go through the motions of a veto," said Sen. Max Baucus, D-Mont., a key participant on the House-Senate conference committee that negotiated the measure, at a press conference following the vote. "I urge the president to skip the veto."

The Senate vote was 81-15, more than the two thirds necessary to override a veto.

The Senate action followed a similar vote by the House on Wednesday.

The farm bill covers farm and nutrition programs for the next five years and will cost more than $300 billion. It scales back some payments to farmers, while boosting aid to dairy farmers when milk prices tumble.

Total spending will climb by about $10 billion, much of that on food stamps, hunger programs overseas and assistance for specialty crops and other programs that are new in this latest farm bill. It also boosts ethanol, particularly alternatives to corn, which lawmakers said could provide big energy benefits for a generation.

Of interest to the north country, the bill also includes a Northern Border Commission, urged by New York lawmakers, that would support economic development programs in the region.

Should President Bush veto the bill, lawmakers predicted that Congress would quickly override him. But there was still a question of how all of that might play out, as the president could "pocket" veto the bill by simply refusing to sign it, in which case it would not become law.

That would delay the process, at least. Sen. Tom Harkin, D-Iowa, said Congress might technically stay in session over a Memorial Day recess to prevent the president from squelching the bill through a pocket veto.

Republican lawmakers said they hoped Mr. Bush would not veto the bill, which had broad bipartisan support in both chambers and is critical legislation for lawmakers to tout in the fall campaign.

The Senate Agriculture Committee's ranking Republican, Sen. Saxby Chambliss, R-Ga., said he hoped Mr. Bush would take the message "that this is a very popular bill."

Among other objections, the White House disagrees about the bill's final cost, saying it would actually spend about $20 million more than the current farm bill — double the increase lawmakers cite. And the administration complained that Congress did not go far enough in reforming farm programs, allowing relatively wealthy farmers to continue receiving payments even as the farm economy prospers.

The bill cuts from $2.5 million to $500,000 the maximum adjusted gross income a farmer can earn and still receive farm program payments, including milk subsidies. But the $500,000 applies only to nonfarm income; the limit is $750,000 for farm-related income.

The White House and some lawmakers sought an income limit of $200,000.

Thursday's passage capped months of tough negotiations that focused on how to pay for the bill without raising taxes. The House had passed its version of the farm bill last July.

"The fact is, farm bills are always complicated," said Mr. Chambliss said.

Despite complaints that the bill fell short on reforms, supporters said it marks a change in direction on farm policies, adjusting the income limits, expanding specialty crop programs and smoothing the way toward more fresh fruits and vegetables in schools. Instead of simply managing what farmers grow, Mr. Harkin said, the bill pays attention to how they grow it, boosting conservation programs.

"I'm still hopeful that the president will sign it," Mr. Harkin said.