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

Comparison on the work for seedbed making tillage

Abstract

1) We investigated the abilities of tilling tines when the water content of two kinds kinds of soil was changed.
(1) In plastic range, the lower water content brings on the smaller size of clod, the relation being linear.
(2) The spading tine, especially L-shaped tine N₈ shows great soil pulverizing effect and is under the influence of water content. But the tine Hn shows relatively high soil pulverization even in high water content.
3) The relation of specific torque for tilling and water content is also linear. The higher the water content, the lower the specific torque.
2) The works by four methods of seedbed making tillage were compared on three kinds of soil of equal water content.
(1) In the case of multi-pass tilling, the weight mean diameter of clod and specific horsepower are proportional to the -n power of number of pass.
(2) The merit of sieving tillage is the homogeneous pulverization of soil and the controllability of clod size. In this case, soil pulverizing effect becomes great when clay content is high.
(3) In the case of one-pass tilling (shield tillage, harrowing rotor and sieving tillage), the work needed to get the weight mean diameter of 10mm becomes about 1/10.
(4) The relations of the works by multi-pass and sieving tillage and clay content of soil are exponential and logarithmic, respectively. The works increase as the clay content higher in each case.
(5) Among the four kinds of methods the sieving tillage brings the highest soil pulverization
(6) The works for seedbed making tillage by harrowing rotor and sieving tillage are less,
3) Our trial calculation for the strength of main parts in case of doing seedbed making tillage by the commercial rotary tiller, resulted in the safety rate of more than 1.3 and assured its security.