Senate Finance Chairman Max Baucus says he’s working on a package of spending offsets that could add billions of dollars to the farm bill’s bottom line — but with strings attached.

Aides say Baucus, D-Mont., would probably dictate exactly where the new money should be spent, including on a disaster relief fund that could cost about $5 billion according to some estimates.

That leaves little additional money for some of the broader initiatives favored by Agriculture, Nutrition and Forestry Chairman Tom Harkin, D-Iowa, who initially proposed a $6 billion boost to conservation programs, as well as increased funding for the fruit and vegetable industry and nutrition programs. Baucus said he aims to mark up his package this month.

Finding extra money to fund the farm bill reauthorization (HR 2419) has been a major challenge for both chambers of Congress. Lawmakers can tag $20 billion onto the bill’s more than $280 billion baseline, as long as the extra spending is offset with tax increases or cuts to other federal spending. Harkin may propose finding some extra money by trimming farm subsidies. This week, he circulated draft farm bill language that would prevent farmers from getting more than $250,000 annually in federal money.

In the House, Agriculture Chairman Collin C. Peterson, D-Minn., also trimmed farm payments and was criticized for including a $4 billion revenue package at the last minute, which Republicans labeled a tax increase. Senate Democrats have said that approach won’t fly in their chamber, and a Finance Committee aide added that Baucus isn’t considering a tax increase.

The big question is how Baucus would pay for the additional $10 billion in spending. Finance Committee members, including the eight who also sit on the Agriculture panel, have been tight-lipped about provisions that might be included in the Baucus plan.

“Hundreds of ideas are on the table,” said Kent Conrad, D-N.D., who has worked closely with Baucus to find cash. “Meetings are under way to flesh all this out. It’s just too soon to say anything.”

A proposal that would hold immigrant workers accountable for making Social Security payments would raise too many budgetary issues, Conrad said, and will probably be tabled. Furthermore, anything touching the immigration debate is too much of a hot-button issue.

Another option would be to allow farmers to opt out of payments they receive for participating in land conservation programs and receive a tax credit instead, Baucus said.

The farm bill debate has been saddled with funding demands from a variety of interest groups that want money to fund new initiatives and expand existing programs. If the Finance Committee decides to dictate in its bill how the money should be spent, those groups have the opportunity to secure cash early in the Senate debate.

The move also would help Baucus get support among the eight senators who sit on both the Finance and the Agriculture panels.

But it also would allow Baucus and Conrad to tie up most of the money in a permanent disaster fund that would help farmers and ranchers who lose crops or cattle to natural disasters, such as those that affected the two senators’ home regions last year. Interest groups promoting conservation, fruit-and-vegetable and nutrition programs worry that the result would be less money for those priorities in the Senate measure than in the House-passed bill.

Some lobbyists said involving the Finance Committee in the farm bill debate also could complicate an eventual conference and stall passage of a bill this year.

Harkin, who had said he hoped to release his bill this month, began shopping his version of the commodity title to lawmakers this week. In addition to lowering the annual cap on how much a farmer can collect in subsidies, from $360,000 to $250,000, Harkin’s language would prevent farmers who make more than $500,000 a year from collecting subsidies.

Earlier this month, a committee aide said a floor debate was scheduled later in September, but Harkin said this week that he is less optimistic about quick action.

“No markup this month,” he said.