jargon777
Chirping
Yah, I am going to echo some of the comments already here -- I think the two biggest things are "natural-like environment" -- this basically means dirt floor. Quail will dig a "nest" spot where eggs will be laid. If they are laying in random places wherever they want, they won't brood.I can't get them a bigger cage, but how do I make their cage as natural as possible? How do I mimic an aviary setting in a smaller space?
The second big thing is "security" -- the quail needs to feel safe. This means minimal disruption from you (e.g. taking eggs, cleaning the coop and causing her stress) and minimal disruption from other quail.
Even with these, it's probably still not going to be likely -- since quail have been bred captively without selection for broodiness, the genetics of modern breeds probably don't favour going broody and rearing young.