Economy of Farm Machinery at Higher Speed (II)

High-speed Economy in Terms of Machine Cost

Abstract

The optimum speed in terms of operating cost of implements and tractor under the assuption of speeding-up or widening of operating width was computed.
After computing field capacity at a certain speed or operating width, operating cost per hour as well as cost per hectare were calculated and then compared with each other.
The following conclusions were made.
1) The economical limit in terms of cost per hour of speeding-up of Japanese plow is about 3 times as large as its conventional speed (Speed-up ratio t=3). Above this speed, widening of operating implements is more profitable. The optimum speed-up ratio in terms of operating cost per hour is a little less than 2.
2) In the case of rotary tiller, the economical limit in terms of cost per hour is t=5, and the optimum speed-up ratio is 3.5.
3) When the cost per hectare is considered, the merit of speeding-up of Japanese plows is quite small and limited in the range of t<2, and there is no clear optimum speed.
4) The speed-up of rotary tiller is always profitable from the view point of cost per hectare. The optimum speed-up ratio is about 3.
5) Economical profit of speeding-up in view of machine costs is greater for smaller machines than for larger ones.