As an article goes there is no detail provided on the build. As an idea for a practical approach to allowing chickens access to grass I give the tractor 4 stars.
As a note though, the size is too small for 6 birds.
This would be a pretty good idea for a few hours at a time. I would run hardware cloth around it though, just in case a predator decides to visit. I wish you had more details on the build.
