14 



BULLETIN 997, TJ. S. DEPARTMENT OF AGRICULTURE. 



average the men on the smaller farms did a somewhat greater amount 

 of custom work with their tractors during the year of the investigation. 

 For the entire 286 farms, 76.3 per cent of the work the tractors 

 did, as measured in days, was drawbar work on the home farm, 8.8 

 per cent was belt work at home, 6.5 per cent was drawbar custom 

 work, and 8.4 per cent was belt custom work. 



Table 10. — Days of 



tractor work on farms of different sizes. 





Size of farm (crop acres). 



Number 

 of farms. 



Days of work on 

 home farm. 



Days of custom 

 work. 



Total 



Draw- 

 bar. 



Belt. 



Draw- 

 bar. 



Belt. 



days. 





7 



28 

 71 

 56 

 47 

 36 

 19 

 22 



11.1 

 17.5 

 19.1 

 22.1 

 26.0 

 28.5 

 31.7 

 32.6 



2.0 

 2.3 

 3.1 

 3.0 

 2.1 

 2.1 

 2.0 

 3.9 



4.0 

 2.3 

 2.6 

 2.2 

 1.3 

 1.9 

 1.5 

 1.0 



5.9 

 3.1 

 3.7 

 2.4 

 1.3 

 1.6 

 0.4 

 4.3 



23 



80 to 119 



25.2 



120 to 159 



160 to 199 



200 to 239 



28.5 

 29.7 

 30.7 



240 to 279 



280 to 319 



34.1 

 35 6 



320 and over 



41.8 







All 



286 



23.5 



2.7 



2.0 



2.6 



30.8 



Size of Farm 

 (Crop Acres) 



Days of Work 



15 20 25 30 



Less than 80.. 



80-119 



120-159 



I 60 - 1 99 



200 - 239 



240-279...... 



2 80-319 



320 and over. 



All. 



Ml Drawbar Work, Home Farm. 

 CD Be/t Work, Mome Farm. 



i Drawbar Work, Custom 

 \ Be It Work, Custom 



Fig. 3.— Days of work per year done by tractors on farms of different sizes. 



On the farms with less than 80 crop acres the drawbar work on the 

 home farm constituted only about 48 per cent of the total; and on 

 those with 80 to 119 crop acres it constituted about 69 per cent of 

 the total. On the farms with 280 to 319 crop acres, drawbar work 

 at home constituted 89 per cent of the total, and on those with 320 

 or more crop acres, it constituted about 78 per cent of the total. 



Figure 3 shows graphically the relative importance of the different 

 kinds of work on the farms of different sizes, and illustrates the error 

 which would be made in assuming that the entire usefulness of a 

 tractor is confined to work where it competes directly with horses. 



The number of days of work done by an individual tractor depended 

 upon the particular field operations for which it was used, the amount 

 of belt and custom work done, and to a certain extent upon the 



