There are many insulation options for pole barns. Choosing the right one depends on your intended utilization of the building, your budget, and the weather your building will endure.
Blown in foam insulation seals air gaps during the expansion process providing the most effective way to insulate your pole barn for energy savings. Those savings come at a price today since this method of insulating is more expensive than others.
Loose Fill fills the air gaps but doesn't seal them. Much less cost than blown foam and effective, but not as effective as expanding foam.
Fiberglass batting comes in various R values and is easy enough to cut and fill air gaps with. No seal is created but filling the air gap minimizes penetration. R30 and R19 for walls and roof.
Condensation blankets prevent indoor condensation and provide minimal (R6) R value, 2" vinyl backed post frame insulation is used as well as double bubble radiant barrier.
These products provide excellent energy savings over long periods of time for pole buildings.