If you put in chunnels, you can arch chicken wire, hardware cloth, or whatever works for you so that they poop on the grass: https://www.countryliving.com/life/kids-pets/a16758721/chicken-tunnel/
If I could figure how to make it work I would do them myself.
All day today I've been playing chicken babysitter picking up the chickens and chicks from areas they shouldn't be in:lau. The grass is truly greener...
And they WILL find a way.