TRACTORS AND HORSES IN THE WINTER WHEAT BELT. 21 
horse teams. On the average farm these operations which were all 
or nearly all done with two-horse teams required 2,059 hours of 
horse labor, or 53 per cent of the total. In the southern area they 
required 58 per cent of the total, in the western area 53 per cent, 
and in the northern area 48 per cent. Much of this work is of such 
nature that it can not be done advantageously with larger power 
units. (See fig. 9.) 
FiG.9.—Two-horse teams were used entirely for haying on these farms. Implements requiring the power 
of more than two horses can not be used advantageously for this and many other kinds of work on 
wheat farms. 
Table 23 shows the number of hours of labor performed during 
the year by the horses on farms of different sizes and the average 
number of hours of work per head. For all farms the horses worked 
482 hours per head during the year. The amount of horse labor 
used on a particular farm depended, of course, not only on its size 
but also on the crops raised, the amount of work done on them and the 
roportion done with the tractor. In general, a greater amount of 
ees labor was used on the larger farms, and the number of hours of 
work per head was also greater on the larger farms. There were 
wide variations, however, even on farms of similar size and type. 
Figure 10 shows graphically the variations in the hours of horse labor 
per head in each area. 
All of the work connected with harvesting, threshing and seeding 
wheat on these farms must be done during July, August, and Sep- 
tember, and since wheat occupies so large a proportion of the acreage 
the amount of work done per year by each horse will necessarily be 
lower than on more diversified farms with better distribution of 
labor. However, on many of the farms visited more work stock was 
