COST OF PRODUCII^G WHEAT. 11 
Over a series of years approximately one-half of the annual pre- 
cipitation in all districts occurred during the four months, April, 
May, June, and July. The lowest annual precipitation was re- 
corded in Keith County, Nebr. (16.62 inches), and the highest in 
Jasper County, Mo. (41.26 inches). 
In Ford County, Kans., and Morton County, N. Dak., the rainfall 
in 1919 was considerably below normal. In Ford County the dis- 
tribution during the growing season was sufficient to insure a fairly 
good yield. However, in Morton County the rainfall was not weU 
enough distributed to produce an average yield. 
SOILS. 
Wheat was grown in the regions visited on fairly deep limestone 
soils, generally well supplied with humus. The lime content was 
especially high in Ford County, Kans., Keith County, Nebr., and 
Morton County, N. Dak., where the amount of rainfall is limited and 
the soluble material has not been leached out. In general, little 
wheat was grown on sandy soils, since this soil type is not so weU 
adapted to wheat growing because of its tendency to blow during 
high winds. 
On these soils no commercial fertilizer was used except in the 
Missouri areas. 
COMPARATIVE WHEAT YIELDS. 
The yield of farm crops in any given region is influenced by a 
number of things, such as soil fertility, weather, insect and fungus 
diseases, crop management, etc. Therefore, the results of any 
attempt to tabulate yields for a single year must be considered as 
suggestive rather than definite and conclusive. Yet when yields 
are tabulated over a series of years an average yield can be arrived at 
which will be of value in measuring the possibilities of the area for a 
given crop grown in that region. 
In Table V the average wheat yields for the State, county, and 
farms visited in 1919 are recorded. In some cases the figures on 
yield were obtained from the Bureau of Crop Estimates, United 
States Department of Agriculture; in others, from State boards of 
agriculture. 
The average yield of spring wheat in the United States in 1919 
was 9 bushels per acre, in contrast with a yield of 8.4 bushels per 
acre for the total spring wheat area surveyed. The average yield 
for aU winter wheat in 1919 was 14.7 bushels per acre, while the 
average yield for the farms surveyed in this region was 14.9 bushels 
per acre. 
The abnormally low yield of wheat in Morton County, N. Dak., 
was partially due to an insufficient amount of total rainfall which 
was not well distributed over the growing periodo 
