Abstract
(1) We have investigated the characteristics of the soil displacement for the rotary and crank type tillaging machines at the rice field of Hokkaido University.
(2) The same results which were described in the summary I-(3), (4) may be applied to hard and dry soil, too.
(3) The relation may exist between M and the number of rice stubbles which are exposed to the unit area on the surface of the field.
(4) But it cannot indicate appropriately the soil displacement with an action which covers the rice stubbles, so-called the inversion by the tillaging machines.
Therefore, instead of the expression called as inversion, we have introduced the mixing grade of soil “M” and defined to indicate the soil displacement with M.
