54 



BULLETIN 907, U. S. DEPARTMENT OF AGRICULTURE. 



COST OF POWER FOR DIFFERENT OPERATIONS 

 HORSES AND BY TRACTORS. 



AS FURNISHED BY 



The cost per acre of power during the year covered by the investi- 

 gation for the different operations for which both horses and tractors 

 were used on these farms is shown in Table 42. The costs based on 

 present prices (Sept., 1921) of feed, fuel, and oil are also shown. 



The 1920 cost per acre of power furnished by horses is given on 

 page 45. The 1921 horse costs are based on an annual cost per head 

 of $85 for keeping workstock, or $1.29 per day of horse labor (see 

 page 45). The 1921 tractor costs are 82 per cent of the 1920 costs. 

 (See page 51). 



Disking in combination, i.e., drawing a disk and a harrow or roller 

 at one operation, was not done with horses on any of the farms, and 

 the cost of power for harrowing and rolling with horses has been 

 added to that for disking to obtain a cost comparable to the cost of 

 performing the two operations at once with the tractors. 



The cost of power for plowing done with tractors during the year 

 of the investigation was only about 70 per cent of that for the plowing 

 done with horses, but with the exception of disking in combination 

 the cost of power furnished by the tractors for each of the other 

 operations was slightly greater than that furnished by horses. These 

 figures, of course, represent the cost of power only, and they do not 

 include either the cost of man labor or of the implements used for 

 the different operations. Neither do they take into account possible 

 differences in the quality of work resulting from the use of the two 

 sources of power. 



Table 42. — Cost of power for different operations as furnished by horses and by tractors. 



[Cost per acre.] 



Operation. 



1920 



Horses. 



Spring plowing 



Fall plowing 



Disking 



Disking in combination. 

 Harrowing, rolling, etc. 



Drawing hay loader 



Drawing grain binder. . 



S2.89 

 3.04 

 .64 

 .98 

 .34 

 .98 

 .59 



Tractors. 



2-plow. 3-plow. All 



$2. 01 

 2.06 

 .71 

 .71 

 .35 

 1.14 

 .61 



S2. 15 

 2.22 

 .59 

 .76 

 .49 

 1.05 

 .76 



$2. 07 



2.13 



.67 



.72 

 .37 

 1.11 

 .67 



1921 



Horses. 



$1.53 



1.62 

 .34 

 .52 

 .18 

 .52 

 .31 



Tractors. 



SI. 70 



1.75 

 .55 

 .59 

 .30 



.91 

 .55 



Note. — The cost of man labor and of the implements used must be added to the cost of power to obtain 

 the totalcost of performing the different operations. The horse costs shown for 1921 are 53 per cent and the 

 tractor costs 82 per cent of the 1920 costs. 



ANNUAL COST OF POWER FOR DRAWBAR WORK. 



Table 43 shows the average cost of the power furnished by the 

 2-plow, 3-plow, and all tractors for drawbar work on the home farm 

 during the year covered by the investigation. On the average, this 



