It was mentioned above that you should deworm your birds twice a year, which I agree with. My quail also live on dirt (we call it a quailviary) and it's built around a tree. What I've found is that my quail (they're bobwhites) love pumpkin. We fed it to them before we knew that it was a great dewormer. We took the hollowed out "shell" of the pumpkin and stuck it in their coop with several holes for them to crawl into it. They went CRAZY for it.It lasted a couple weeks before decomposing to the point where they couldn't eat it anymore. If you can still find/grow some pumpkins, I'd recommend doing so. Pumpkins also can be stored, which is always a plus!
I STRONGLY second the hollowed out pumpkin idea (plus it's so cute to see them hanging out inside). Just keep an eye out for mold.