Life in Christian County, Kentucky... Life in The Upper South...
Across Christian County, KY, and (I suppose) other parts of the South where dark tobacco is produced, the firing of the leaf has begun. ("Leaf" is sometimes used as a plural when talking about tobacco.)
In this photo, you can see a heap of sawdust and a pile of hardwood slabs (sides of logs, cut off to square them up for lumber). Sawdust and slabs are placed in trenches in the dirt floor of the barn and set afire. The air to the barn is restricted so that the fire smolders and creates a lot of smoke. The smoke rises through the leaf, coating and flavoring it.
Inside the barn, someone is getting the fire started. When it has started good, he'll close the doors and probably also prop them shut with several long 2x4's just to make sure they don't come open, let in too much air and burn down the barn.
I've always thought that all that smoke must be really bad for tobacco farmers. After a morning of tending barns, they reek of smoke and I'm sure they've breathed a lot of it.
UPDATE: For a view of a barn that's closed up and smoking, see Scenes of Late August.