1- Store firewood wood kindling. Because we're building lots of things, I end up with plenty of little scrap pieces of wood. Cut into small pieces, they make excellent kindling. But where to store them? Old feed bags, of course.
2- One of my friends creates shopping totes out of them. Great idea!
3- Another friend uses them to carry horse manure. Transporting the manure this way saves her car from becoming a compost bin on wheels.
4- Transporting grass clippings. I do a LOT of mowing for harvesting grass clippings. I've found that transporting the clippings in trashcans is the easiest and quickest way to load them up and unload them at the garden. But when I mow some place other than my own property, I usually mow for two hours. That much mowing quickly fills all my trashcans, leaving me with a giant pile still to be moved. Old feed bags now come in handy. I fill bag after bag. That way I can leave the bags sit there overnight until I can return to retrieve them. The bags are easy to move, unload at the garden, and empty out.
5- Lining for the pallet gro-boxes. The pallet boxes need to be lined with something to hold the soil and moisture in. Old tarps, old plastic, and old feed bags all work. So once the feed bags get a little ratty from one of their other tasks, they become gro-box liners,
6- Trash bags. Sometimes I need a stout bag to hold trash. Feed bags fit the bill quite nicely.
7- Store shredded paper. I save shredded paper to use in the chicken nest boxes. I also save sawdust for the same purpose. Old feed bags work real nice for storing this material. The bags don't get holes in them plus they are easy to haul around.
8- I tried once using them as giant growing bags to grow potatoes. They worked but were difficult to deal with. They tended to sag and tip over. And the plant roots got too warm, in my opinion. But with a bit more refinement, I bet they could be fine for growing plants in. You could probably get two or three crops out of a bag before the sun weakened the bag too much.