New garden bed/chicken tractor system

I haven't posted anything for a few days because I've been busy building a new bed/tractor system. I took inspiration from Patti the Garden Girl who built a similar system. Basically it is a series of three shallow 4' by 8' garden beds and one chicken tractor that fits inside all three. The plan is to put chickens in there for a season, let them eat, scratch, poop and make the soil better and then move it to a different bed. So at any given time, 2 of the 3 beds will be in use, and the other one will be "fallow" while the chickens improve it for the next planting.
I plan to get an couple new chicks in the fall and this will be their home for a bit. I put two nest boxes in the chicken tractor in case I want to let some of the already laying hens scratch around in one of these from time to time. I was looking into getting meat birds as well, however according to my calculations bird+feed will be somewhere around $8.50 per 5 lb bird... It doesn't seem to be worth the trouble.

I also put in two Honey Mesquites (a native tree that drops pods I'll use to make flour) which you can see, still in pots, in the foreground of the second picture here. They were very cheap, $15 each and already taller than me.

The beds
Basic chicken tractor frame
Basically Complete!
I need to add a gate latch to one of the doors and a perch then it will be totally done. I will photograph it when I get it set up in place with the tractor mounted on one of the beds. Another advantage to this is that it should be totally sparrow proof. Thanks to me, Central Phoenix should have the most organic wild birds of any major metropolitan area.