Some experiments on the rotary tillage were carried out, and the results are follows;
1) When the cutting width of tines is same and the working efficiency (area efficiency) is equal, it is better for reducing power to make the tilling pitch (length of a slice) large and the numher of tines less according to the tilling pitch.
2) When the cutting width of tines is not same and yet the working efficiency is equal, it is better for reducing power to make the tilling pitch small and the cutting width of tines large according to the tilling pitch.