I have been working such a diet out myself. My advice is to focus on a few things to get the main components of their diet and use a bit of diversity (like in the wild) to ensure you get the full range of nutrients for the birds from producing your own feed. For protein I think culturing mealworms, superworms, and perhaps a few other insects along with the water plant duckweed is what I am going to do. Duckweed is higher in protein then soy and has a better amino acid profile then most plant sources, according to the linked article japanese quail like it. It can double its size in 24-48 hours. Through out the winter I will keep my best breeders and egg producers, and throughout the warm months if I go for meat production Im going to focus on duckweed en mass grown in cheap kiddy pools with water from my fish. For the rest of the diet I am growing a range of seeds. Amaranth, millet, sunflowers, sorghum, corn are all easy to grow here, but I will be using others as well. Keep in mind all things things have some protein as well along with other nutrients, so you would be bumping it up with the insect and duckweed not necessarily leading with them. Im still working out all the details but for cheap easy protein production you cant beat growing duckweed in the warm months (you could do small amounts in windows in winter to, if you wanted). For calcium I am growing sowbugs AKA pillbugs. The type that roll up are easy to culture in many ways. It isn't actually an insect at all. It is a crustacean, so it is a shell like a oyster. Sadly I can't find info on its total nutritional value but I have found reference of people using it as a source of calcium for other types of birds, and people raise them for different types of reptiles as well. coturnix quail are more efficient with calcium then most birds I have read so having their own shells, the sowbugs and if you wanted crushed snail shells that were grown with the duckweed. So many alternative sources.
You can fertilize the water for the duckweed many many ways, so no issues there. It doesnt need the water to be deep either. It is a good thing to feed fish as well, and carp or tilapia would be happy on a diet of duckweed as well, and can be raised cheaply if you want to do it that way. Tilapia or common carp (mirror carp were bred for the table, growing very fast, breed easily and are tasty on the right diet in good water) in cheap 55 gallon drums with duckweed growing on old tank water from the fish, which feeds your birds and your fish, the water then going from the duckweed pond through a sand filter and back to the fish can be a good cheaply accomplished route to take, or for just the birds of course, just mentioning it though.
So basically you will likely have to fill in the details yourself. It will take some time adjusting to what you grow best and works best for you to get it ideal, but you can indeed meet all their nutritional needs with home grown things. It all depends on what your willing to do. If you are all ready a gardener, it shouldn't be hard at all.
http://www.microponics.net.au/?p=181
