In California for valley quail habitat restoration fish and game dig a shallow pit and put an old car hood or other piece of scrap metal over it with just enough space left open on one side for the quail to go under it, then they'd throw brush all over the top of it. Gives them a little protection anyway.
My opinion on restocking is never popular but is supported by most state conservation departments as well as the publications of many biologists in this field, so please don't be offended.
If releasing quail actually worked it would have already. Some states started stocking bobwhites as early as 1899. All types of game birds were released en masse in the first half of the 1900s. The effects obviously were minimal at best but mostly non existent since the bobwhite population is still in such bad shape. These were the results with professional biologists and a full support staff doing their best to get bobs to take hold. Cage raised birds are just plainly inadequate for life in the wild.
http://www.clemson.edu/extension/natural_resources/wildlife/publications/fs7_bobwhite_quail.html
http://www.noble.org/ag/wildlife/stockingbobwhite/
http://mdc.mo.gov/blogs/more-quail/why-we-dont-stock-quail
http://www.agfc.com/resources/Publications/bobwhite_factsheet.pdf
I'm not trying to stop you from doing it, just show you that it's been done on a scale a hobbyist couldn't hope replicate and still saw no success. If I were going to try to do it I'd try it out of a
surrogater which is a special brooder for quail but costs a pretty penny, and honestly has no shown proof it can lower mortality rates by keeping quail out of human contact from hatch to release.