20 
workers per farm, the average crop-acres and value of crops per 
worker, the average value of all crops per crop-acre, the average 
value of machinery per farm and per worker, and the average net 
income per farm operator by States, and Figures 21 to 26 the dis- 
tribution of farms, land in crops, the principal soil regions, the 
average length of growing season, the average annual precipitation, 
and the principal agricultural regions of the United States. Figure 
27 shows graphically the relative importance of each of the princi- 
pal crops grown in each State, and Table XVI and Figures 28 and 
29 the distribution of different sizes of farms in the various States. 
Topography, as a rule, has more to do with the average size of 
farms and fields predominating in any given area than any other 
factor. In the Central West the land generally lies fairly smooth, 
with few streams or ravines to cut up the fields. This condition 
encourages the laying out of large fields and the use of large ma- 
chines or power units, with the result that fairly large farms pre- 
dominate in this area. On the other hand, in the Eastern and 
Southern States the land is usually cut up with many hills, ravines, 
and streams, making small and irregular fields necessary, which 
discourages the use of large machines or power units, and results in 
a predominance of relatively small farms. (See fig. 28.) Types 
of crops produced also have much to do with the size of farm in 
a given area. Where crops are produced which require a relatively 
large amount of labor or power and have a high value per acre the 
farms usually average smaller than in areas where the crops pro- 
duced require a relatively small amount of labor or power. 
SEASONAL DISTRIBUTION OF THE USE OF LABOR AND POWER 
ON FARMS 
It is extremely difficult to obtain definite information on the rela- 
tive labor and power requirements of the different types of farming 
on account of the great variations that exist. Table XVII, hov/- 
ever, shows the percentage of man and horse labor devoted to the 
different farm enterprises, and Figures 30 to 36 the distribution of 
labor for several types of farming as determined by a number of 
farm-management surveys. ^^ 
Probably the most serious difficulty encountered in the efficient 
use of power and labor in agriculture is the extreme seasonal de- 
mands of many farm operations. In each type of farming followed 
there is usually some single operation v/hich requires a large amount 
of power to complete the work within the seasonal limits permissible, 
and it is usually this operation that determines the minimum amount 
of primary power that must be kept on any particular farm. In 
the Corn and Cotton Belts this operation is usually that of planting 
or cultivating; where hay is an important crop the harvesting of 
the hay is usually the determining operation, and in the small-grain 
regions it is sometimes the preparation of the seed bed, and in 
other cases that of harvesting or threshing. (See figs. 37 to 47 for 
examples of the distribution requirements of man and horse labor 
for the principal crops and livestock produced on farms in the 
United States.) 
10 A more complete discussion of types of farming and the distribution of labor on farms may be found 
in Farmers' Bulletin 1289 and U. S. Department of Agriculture Bulletins 814, 961, 1000, 1020, 1181, and 1271. 
