To solve the problem of the difficulty in crushing the surface clod in the digging of a field at a low rotational speed in the case of finely crushing the surface clod with a rotary tiller while leaving large clods in the inner part to improve the root spread of the growing crop.
Tilling tines 1 are attached in arranged manner to a laterally extending tilling tine shaft 2. The upper part of the shaft is covered with a main cover 3 and the rear part of the shaft 2 is covered with a rear cover 4. In a rotary tilling tool having the above structure, a swinging screen 8 provided with a plurality of longitudinal teeth 6, 6... and lateral teeth 7 protruding backward from the lower end of the longitudinal teeth 6 and swinging in longitudinal direction around the side of the main cover 3 is placed between the tilling tine shaft 2 and the rear cover 4.
TAKAHASHI HISASHI
NAGAI SATOSHI
