抄録
the effects of mixing tillage by rotor-bucket machine on improvement of subsoil under these fields. Some of the results obtained are as follows :
1. Thickness of both A and B horizon of the soil profile increased by mixing tillage by rotor-bucket machines.
2. The content ratio of soft-rocks decreased by this treatment and the hardness of soil also decreased.
3. Physical properties throughout the soil profile were improved especially in three-phase distribution.
4. Mixing tillage by rotor-bucket machine enhanced the growth of fine roots and yields of tea.
