I don't have a truck, and do something similar. But instead of totes, I use 15 gallon black plastic nursery pots. When I go to pick something up (not from a nursery) such as free city mulch or horse manure, I take a pitchfork, and fill each one, and load them into the back of my small SUV. I can fit in 11 of them into the back. That's just under 1 yard.
When full, these are easy for me to move, one by one. And no extra shoveling. I can put one or even two on a dolly and move them to any part of the yard where they are needed.
If you watch Craig's list, or know a landscaper, you can get used ones for not that much money, or even free.