BeeKissed has been doing DL successfully for years. Her set up is hoop coop over dirt floor, perfect for DL management. She routinely adds moisture when the litter gets dry. She has a nice video. I'll invite her over here to chime in, and perhaps she'll bless us with her video.
I can tell you that I've had vastly different experiences with DL. My first coop is a cattle panel hoop, over all dimensions are approx. 8 x 8, with 6' center height. The back 4' has a loft that is raised up 2' from the bottom of the panels. So, there is a lower level that sits on the ground...
What is the cart made of? Metal? If so, I fear that your DL will eat through the metal before you get a good composting action going. Chicken poop is very caustic. Here's my suggestion to you: If you are in the snow belt, you'll not be moving that tractor much anyways during the winter. Is...