PROBLEM TO BE SOLVED: To allow a straw caught in a skid to be smoothly carried to a tillage jaw side and to perform elimination processing from a field surface by means of a tillage jaw.SOLUTION: At least one lower part of right/left side parts of a rotary machine frame 2A supporting right/left both ends of a jaw shaft 6 including plural tillage jaws 5, a skid 7 is arranged which has a skid front part 7A curved upward. The skid front part 7A is positioned on a side of a tip of the tillage jaw 5. The skid 7 includes on a bent skid front part 7A a waste straw tool 8 which guides a caught straw F to the tillage jaw 5 side.SELECTED DRAWING: Figure 2