BOZEMAN (AP) -- Landowners will soon be able to claim larger tax deductions for placing conservation easements on their property, under a provision included in the pension overhaul bill that President Bush signed Thursday.

The new law will allow farmers and ranchers who derive more than half of their income from agriculture to deduct 100 percent of their adjusted gross income from federal income taxes for up to 15 years after their land is placed in a conservation easement.

Other landowners can deduct up to 50 percent of their income for up to 15 years.

Previously, landowners could only claim deductions of up to 30 percent of their incomes for up to five years.

The bill also increases the federal income tax deductions of individuals operating as a C-Corporations from 10 percent to 50 percent. Many family farms and ranches operate as C-Corporations for tax purposes.

"Passage of these conservation incentives will allow more Montana ranch families to protect their ranch heritage," said Jay Erickson of the Montana Land Reliance.

"The package of conservation tax incentives helps level the playing field so traditional farm and ranch families of more limited means can conserve their property," Erickson said.

The total tax deduction can't be more than what the gift was worth and the law only applies to easements donated in 2006 and 2007.

Under a conservation easement, property owners agree to give up future development rights but are still allowed to own and work the land.

The conservation easement legislation was co-authored and sponsored by Sen. Max Baucus, D-Mont. Also voting in favor were Sen. Conrad Burns, R-Mont., and Rep. Denny Rehberg, R-Mont., the Montana Association of Land Trusts said in a news release.

The pension bill also paved the way for the $50 million Going-To-The-Sun Road repair project in Glacier National Park. Baucus' office said the project was approved in the 2005 highway spending bill but the money had been held up by a technicality.