Landowners - whether working farmers or landed gentry, are usually nice people when approached in a friendly and apologetic manner...I'm sorry to trouble you, but I've had to land in your field....
The promise of a bottle of Famous Grouse and a couple of tickets for a ride in a glider at the home club usually cheers up the owner, and perhaps his kids would like to sit in the aircraft and have their photo taken? etc etc.
Balloons are a different matter. They know when they launch they are going to land out, and usually carry a map intensively marked with hostile territory! The commercial balloons carry up to 12 pax, who have paid a fair amount to ride, and the noise they make when firing off the heaters can frighten livestock.
Gliders and small aircraft generally intend to arrive at an airfield when they set out.