So, here is my story of how I have tried to use my chickens to actually improve my ground. Sorry the pics could tell it better if I had thought to take them all from the same spot but here goes.
The chicken yard is 1/2 acre of flat ground that had been base rocked about 4" deep. Surrounding that is vast wooded areas. My focus was on the rocked part.
It all looked like this
I penned 75 three month old birds in one section of electro net for a total of 20 sf per. I left them confined for three months. I only let them out when cleaning the coop. I used pine shavings in the coop (horse trailer) and tossed the old bedding into the pen. I did not have any wood chips at the time. I did not attempt deep litter in the trailer. I did not till or otherwise turn the ground.The bits of green you see below is nothing but tar weed and small brush.
After three months the ground was very heavily impacted and had a residue of manure and shavings over the whole 1600 square feet.
About that time the wood chips arrived so I pulled down the fence and let them loose to manure the wood chips pile as it broke down some.
I seeded the whole flat, the area where the chickens had been as well as the rest of it so I could see the difference between where they had been confined and the rest of the flat. The coop was not moved and the chickens where not kept off the area. They preferred to stay on the chip piles.
This is how it looks now You can just see the front of the trailer in the upper right corner.
A view from above you can see where their impact stopped the seeds did not germinate.
Not the lushest pasture out there, but it is a very significant improvement.