Grazing Frames

I read an excellent article today about grazing frames. I wonder if anybody here has made grazing frames before that could fill me in on how well they work. The author used them in lieu of rotating through paddocks. Pros and cons? How would this affect the microbial life in the chicken yard, if at all?

http://www.thegardencoop.com/blog/2012/02/07/grazing-frames-backyard-chickens/

I have seen a similar technique used with success. They are very handy for small spaces.
It will prevent them from turning an area into a 'moon scape' (which they can do quickly).

Just remember that you do need to provide them with areas to scratch in, as well.

You're absolutely right, John. My ladies like to take their dust baths en masse, so I would venture to say that you would need enough space to bury each of the gals with several inches left over on each side.

The grazing frames also limit the amount of worms/bugs they can get. Also soil minerals.
"Creepy-Crawlies" are their primary source of protein. They do need access to soil...just not ALL of it.

P.S. The system I saw did not go to the expense & labor of making the frames.
They just laid strips of the hardware cloth on the ground. It is enough to keep them from scratching.
Quicker/easier to move. Also saves the cost of the lumber (which will rot out quickly on the ground).