Studies on Deeper Rotary Tillage (II)

Field Test (I) Tilling Patterns and Tilling Reaction Force

Abstract

Field tests of deeper rotary tillage were done in clay soil and sandy soil, and following results were obtained.
1) When the rotational directions and the ratio of tilling depth to rotor radius (H/R) were changed, four tilling patterns that had different characteristics of throwing tilled soil backward respectively were observed. (Fig. 5, 7)
2) Throwing tilled soil was superior when down cut tilling under H/R smaller than 1.0 and up cut tilling under H/R greater than 1.0. The former might be favorable for common rotary tillage, the later might be favorable for deeper rotary tillage.
3) Tilling reaction force acting on a blade was the largest when the bottom soil was cut upward by the curved blade portion on both cases of down cut tilling and up cut tilling in sandy soil.
4) On the case of up cut tilling under H/R greater than 1.0, it might be important for design of rotary tiller for deep tillage that the shapes of a blade and tilling cover should be improved to throw the soil better.