Jeff, its not happening.
I'm unsure where you may have gotten the idea from, who may have led you astray, but accept that its not happening.
Supporting a modern chicken requires a complete diet that is almost impossible to make from purely plant sources - and even if you could, the likelihood that you have a property which would allow you to grow (in quantity, and cheaper than available commercially) corn, a cereal grain like hard winter wheet, one or more seeds (sunflower, white proso millet, etc), and legumes (soy, winter peas, field peas) in the ammounts needed to support your chickens, dry and store them for months when they aren't in season, and provide the necessary enzymes and treatments to reduce their anti-nutritive properties is near 0. Even then, your feed would be deficient in a number of key amino acids for your chickens to thrive.
Most "make at home" mixes worth a damn (and I've seen three of them on BYC in the past six+ months) make up the difference with a bag of fish meal. Is your property also on the coast, or you have access to a large and well stocked body of water? Barring that, you could use "meat scraps" from the turn of last century recipes - meaning there is some other animal(s) you are supporting, which you routines slaughter to meet the chicken's dietary needs.
I have one of the most tolerant growing climates in the US - zone 8a - a large pasture, and poor soil (because all the good soil is already being used for farming, as is all the average soil, with the addition of lots of fertilizers). I also live in an area with relatively steady seasonal rainfall - we average 4" Jan, 4" Feb, 5" Mar... and avg 58-62" (depending on source) of rainfall annually. I've deliberately seeded that pasture with a mix of grains, legumes, grasses, herbs that are perrenial, self seeding, and suited to my climate - so I don't have the expense of maintaining heavy equipment for conventional modern farming. Best I can do is bend my feed curve - about 15% right now (maybe less) while everything is out of season, and close to 35% thru late summer and early fall as things come into season.
Last month, we recieved less than 1" of rain, and are already 4" low on the year. My pasture is hurting. My chickens likely ate most of the pounds of fresh seed I added to try and establish new crops for their diet as result. Even when you do everything right, when you live this close to the land, Nature can still kick you where it counts.
A location in your profile would help us help you. But your stated goal? That needs to be reassessed.
/edit for clarity of tone. This is not meant to suggest that you can't do it better than I. To the contrary, I'm in my second half century and have largely worked desk jobs all my life. Nor is my wife in a condition to assist much, physically. I would expect you to do better than I, in similar circumstances. Rather, its to suggest that even with most every natural advantage, its still extremely hard (if not actually impossible), and that their are conditions beyond your control or likely ability to compensate for.