Studies on the Seedbed Making Tillage by Rotary Tiller (V)

In the Case of Harrowing Rotor

Abstract

This is a report on how to make a seedbed by using harrowing rotors. Mainly the degree of pulverizing was examined when the revolving speeds of the harrowing rotors were varied with three types of harrowing tines being tried.
1) This method features combined application of the harrowing elements and partial harrowing of tilth.
2) Pulverizing pitch and cutting speed of the harrowing tine have shown a power functional relation among the weight mean diameters of the clod.
3) Between breaking ratio and non-dimensional term (D_w1-h/P_i-h, V_c-h/V₁) related to the revolving speed of the harrowing rotor there existed an exponential relation.
4) Although the pulverizing performance of the soil was slightly affected, a good result was obtained either with h₂ (knife tine) and h₃ (L-tine).
5) The harrowing element viewed from the pulverizing extension index has shown a higher value when shielded and was found that it gave a higher pulverizing efficiency.
6) The working performance and power performance have been influenced considerably by shielding or non-shielding.
7) If the mechanical operating condition were taken as a factor when the three elements, vis., the tilling rotor, shield, and harrowing rotor, were jointly used, the weight mean diameter of the clod of the seedbed may be expressed by the following equations:
D_w2=[1-(A₂B₂^π2)]×(A₀⋅P_iⁿ¹)⋅C_T^-n2, (mm)
or
D_w2=[1-(A₃B₃^π3)]×(A₀⋅P_iⁿ¹)⋅C_T^-n2, (mm)
where
π₂=D_w1-h/p_i-h, π₃=V_c-h/V₁, D_wi-h=(A₀⋅P_iⁿ¹)⋅C_T^-n2