Floor of run?

[PollosMama]

I'm trying to figure out what to use in the floor of my partially covered run. Sand, mulch, straw? What do you recommend? It's currently dirt. I'm looking for something that will keep the smell down, make cleaning easiest, etc.

 

[Foster's Freehold]

You could do deep litter with hay or wood chips. Both keep down smell, clean up is a matter of tossing scratch into the run for the chickens to turn. It also promotes bug growth underneath so they can look for those too.
Wood chips would be a bit better in the uncovered part, it doesn't break down as quickly.