We're building a new run and I'm going to try the Justin Rhodes wood chip method for the run. Seems like a no brainer to let the chickens compost the wood chips and annually use it for my gardens. Currently I use sand in one run (which works great) and the other is dirt with straw I throw down as I have feathered feet bopping around. Growing anything in my runs is futile with 20 large birds. They free range almost everyday and still wear down any run quickly. Current run sizes 7x15 and 13x20 (365sq ft) both have perches, bales, etc for upward mobility. Both are attached (but separate) to a 8x17 shed/barn.