From the looks of things, as someone above mentioned so long as you attain the landowner's permission there should be no problem.
You may want to check out 'Rule 5' though - as far as I'm aware, the only exceptions to the 500' rule with regards to take-off and landing must be under the circumstances that the manoeuvre is carried out at a 'Government, Authority or Licensed aerodrome'... not a school playing field.
But that's just from what I recollect of Air Law - have a look yourself.
Cheers, Jack.