Chickens on a small lot, and thus confined to a small area, really require a mulch of straw or similar. I've seen sawdust used, and I've shoveled wet sawdust, and I was not thrilled. All it does is pack down and stink.
I use straw in the bottom of the coop (4x4'
, at least 4" or 5" deep, and every late afternoon I scatter a good handful of scratch over the straw. Looking for the tasty little nuggets, they kick and fluff the straw, helping to keep it dry. Much of the manure sticks to the straw.
If you just throw down some kind of mulch and don't give the chickens a reason to work it over, they won't. It just mats down and stinks. And you can't leave it there forever, either.
Chickens are relatively low-care, but they're not no-care.
I will be building a chicken tractor soon, I hope, but it is mainly to confine them in the areas out side their pen to prevent crop damage (esp young plants). I intend to move it two or three times a day, depending on the site vegetation.
Most chicken tractors are deliberately left in one spot long enough to kill everything -- that's the reason they're using chicken tractors in many cases. And they usually use a higher density of chickens than I do.
But I had to learn the hard way that chicken tractors and coops are two entirely different things -- a coop can be fairly predator-proof, and chicken tractors aren't, unless you make them so heavy that you can't move them easily. My armored chicken tractor must have weighed over 200 lbs -- big mistake.
My new tractor will be 1x2s or 2x2s with chicken wire and a small hatch on the top with some shade provided.