I took a long-ish trip north and stopped to snatch a scan of some rather large hay bales in a field off the road. These actually stood about four feet tall and maybe six feet long. So I thought it would be a perfect subject for a good scan... on the shadow side of the bale. It turned out pretty good. You can see the pinching of the actual bale down the middle. I hope this helps your agriculture styled scenes. :)
These photoscanned models have 8k maps for reasonable UVs, color, depth & normals. Enjoy!