ROTARY BLADE FOR CUTTER

PROBLEM TO BE SOLVED: To provide a rotary blade for a cutter for performing cutting by sure sending in a root part having a thick stem and for surely carrying out holding and cutting even in a tip part having a thin stem, by arranging rotary blades forming a recessed edge part on the outer periphery and rotary blades having no recessed edge part on the outer periphery at specific positions. SOLUTION: A high-speed cutter shaft 11 and a low-speed cutter shaft 20 revolving in the opposite directions mutually are installed in parallel and plural rotary blades having sawteeth on the outer peripheries of the cutter shafts are arranged in parallel. Rotary blades having formed recessed edge parts on the outer periphery are laid at a side to which the plant foot part of waste straw is sent and rotary blades having no recessed edge parts on the outer periphery are laid at a side to which the ear tip of waste straw is sent. In the operation, preferably one or more rotary blades having formed recessed edge parts on the outer periphery are arranged at the side to which the plant foot part is sent and one or more rotary blades having no recessed outer periphery parts on the outer periphery are arranged at the side to which the ear tip part is sent in the rotary blades at both the ends in cutting the waste straw in the length direction of the waste straw in the arrangement of the rotary blades.