I love that and would've done mine that way if I had unlimited space. For a smaller flock, I've also seen a chicken tractor sized to fit on top of a raised bed garden system: you place the tractor (and possibly some partially finished compost/leftovers after harvest) on a raised bed, let the girls dig for weeds/worms/grubs for a few weeks, then move them and the tractor on to another raised bed while you allow the finished bed and manure to "age" a bit so as not to burn seedlings. You end up with a fertilized, cultivated bed, and the girls are happy. Looks like a sweet system if you have a set of raised beds of standard sizes and practice seasonal rotation. In the summer when all's growing, the tractor can be used in the yard. This also requires significant space.