Cereal crops like wheat, barley, and oats leave behind straw swaths when the "Create straw swaths" mode is enabled on a combine harvester.
It is highly recommended to back up your original data folder before making changes. LS19 REAL STRAW TEXTURE
If you are using a modded map, the textures may need to be placed within that specific map's folder rather than the base game files. Straw Mechanics in FS19 Cereal crops like wheat, barley, and oats leave
For context on why these textures are valued, straw is a critical resource produced by: Cereal crops like wheat