My friend Janice loves cotton- it says so right in her Twitter handle, @JPLovesCotton. She sent me this picture from harvest in her part of the world today.
That's a John Deere 7760 Cotton Picker at work. The round things out in the field with it are modules. The 7760 has a built-in module builder and handler. Cotton is packed into a round module, covered with wrap, then rolled out of the builder chamber on to a handling ramp. When the driver reaches the headlands, the module is rolled off. It's non-stop cotton harvesting.
Here's a 7760 working.
The modules themselves are pretty hefty- around 8 feet wide, 7,5 feet tall, and in the neighborhood of 5000 lbs each. The round shape gives them extra protection from elements, since water doesn't pool and there's wrap to keep them off the ground.
I haven't seen a 7760 running in person yet, although I really want to some day. Maybe some year I'll get to take a Harvest field trip!