COST AND UTILIZATION OF POWER ON FARMS. 11 
The practices with regard to keeping workstock and raising colts 
on these farms where tractors are owned are probably not exactly 
typical of all farms in the same communities, but the figures do indi- 
cate that there has been a marked decrease in the number of colts 
raised on these farms, and that at the present rate not enough colts 
are being produced for replacement. 
SIZE OF FARM. 
On farms of similar type, the number of crop acres is closely corre- 
lated with the amount of horse and tractor work, and for the pur- 
pose of comparing these items the farms here have been arranged 
according to the number of crop acres in each. The area in rotation 
pasture during the year of the investigation has been included in 
the crop area, so that the number of crop acres in a farm as used here 
is the total number of acres in the regular rotation. Land in blue- 
grass and other land which has been in pasture for a number of years, 
even though improved and tillable, was not included in the crop area. 
Of course, the rotation on different farms and in different areas 
varied somewhat, and the practices on different farms also varied, so 
that the number of crop acres in a farm did not determine entirely 
the amount of power required for operating it. 
The number of crop acres in the different farms was as follows : 
Farms. Crop acres. 
7 : ; Less than 80 
28 80 to 119 
71 120 to 159 
56 160 to 199 
47 200 to 239 
36 240 to 279 
19 280 to 319 
22 320 or more 
These figures indicate that most of the tractors owned in these 
areas are on the larger farms. The average total size of all farms in 
the 6 counties is not over 120 acres. 
On the average, the number of crop acres on the farms visited is 
about 80 per cent of the total acres. If the same ratio of crop acres 
to total acres holds for all farms in these counties, the average number 
of crop acres for all farms is not far from 100. In other words, some- 
thing like half the farms in these 6 counties contain 100 or less crop 
acres. But only 35 of the 286 farms on which tractors are owned, 
one-eighth of the total, contain less than 120 crop acres. 
The number of acres in the different crops on the farms of different 
sizes is shown in Table 7. In each group, corn is the principal crop 
and occupies a greater acreage than all the small grains combined. 
