As far as actually using the ground your sorted.
Trouble is, if a third party was to get hurt, you need to be covered by 3rd party liability insurance. Being as that a marker is legally, an airgun, you might find that BASC mebership will cover you, also means you can keep the bunny population under,(NOT WITH YOUR MARKERS...OBVIOUSLY!!!) which will keep the cricket club happy!
But, best to speak to the UKPSF, about the insurance, and that sort of thing.
Gaz