Astro turf.
Talk to people like esporta or the larger LA installers, once a council pitch starts ripping up they have to pull the lot up and replace or risk punters suing them.
The guys will let you have it for free if you collect tis very heavy en masse, looked at this myself an age ago lost all my contacts.
Remember [hope not telling you to suck eggs] dont just lay it on the ground over grass etc or will be smellsville in no time, turns your stomach and flies a plenty.
Strip back to bare earth, drain channels of pea shingle fill and take to perimeter, cover with sand and tension fix the turf or it willl be you getting sued:tsk: [a waiver warning of ruts etc etc and you may trip will not cut it, duty of care prevails] hence why councils strip it up regularly.
Good luck, where will you be based.