20 
BULLETIN 997, U. S. DEPARTMENT OE AGRICULTURE, 
the land, following with the disk drill drawn by horses. In Illinois 
and to a less extent in Indiana the land planted in oats was prepared 
with the tractor. The cornstalks from the preceding year were broken 
with the disk and the seed bed put in shape for planting the crop. 
On some farms the tractors had not been used to any great 
extent for disking freshly plowed ground in the spring, because of 
danger of packing the soil. On many of the larger farms, where it 
was necessary to supplement the tractor with horses in preparing 
the seed bed, horses were used for disking while the tractor was being: 
used for plowing. 
The fact that a smaller portion of the disking than of the plowing 
was done with horses was in the main due to these two conditions. 
Of the 286 operators, 284 did some disking during the year. In 
Table 17 is given the number of men on the various sized farms 
who did all then disking with their tractors, those who used both 
tractors and horses, and those who used horses only. The disking 
has not been separated into spring and fall work, or into work on 
plowed and unplowed ground. 
Table 17. — Kind of pouer used for disking on farms of different sizes. 
Size of farms (crop acres). 
Number 
of 
farmers. 
Farmers 
using 
tractors 
only. 
Farmers 
using 
tractors 
and 
horses. 
Farmers 
using 
horses 
only. 
Less than SO 7 
80 to 1 19 2S 
120 to 159 ■ 70 
460 to 199 56 
200 to 239 46 
240 t o 279 36 
2S0 to 319 19 
320 or more 22 
Total 2S4 
Per cent 100 
4 
1 
24 
3 
39 
2S 
33 
IS 
24 
20 
IS 
17 
10 
9 
S 
13 
160 
38 
Sixty-four per cent of the men with less than 160 crop acres. 56 
per cent of those with 160 to 239 crop acres, and 47 per cent of those 
with 240 or more crop acres did all their disking with tractors. The 
fact that more than half of these men did all the disking with their 
tractors and 95 per cent used them for part of the work indicates 
a well established place for the tractor in tnis work as well as in 
plowing. 
Harrowino. rolling, planting, and packing. — In most cases not 
more than two of these operations were performed on a farm during 
the year. Six operators had not used spike-tooth or spring-tooth 
harrows, rollers, plankers. or packers during the year, but had fitted 
their ground entirely with disks. 
When tractors furnished the power, the implements were gener- 
allv used in combination rather than individuallv. the most common 
