Bargain Sale

In a bargain sale, land is conveyed at less than its fair market value, increasing the chance that a land trust or government agency can purchase it. By negotiating a mutually agreeable price, the transfer is more affordable for the land trust.

Advantages
It provides cash, avoids some capital gains tax, and entitles you to a charitable income tax deduction based on the difference between the lands fair market value and its sale price.

Source: http://www.ctconservation.org/conservationoptions