THE EFFECTIVE USE OF LAND AS SHOWN BY YIELD 5 
States Department of Agriculture and many of the States, annual 
crop-yield figures by counties are now available for much of the 
United States. 
For foreign lands, including the countries of northwestern Europe, 
little was available in the way of statistics of yield until the last 
quarter of the last century. Official publication of crop-yield figures 
in western and central Europe began in the seventies and eighties 
with one exception, France, where yield estimates have been avail- 
able since 1815. 
The materials cited above furnish practically the only official and 
authoratative data available on the history of crop yields for coun- 
tries and minor civil divisions. 
TREND IN CROP YIELDS IN THE UNITED STATES AS A WHOLE 
During the last half century great changes have been taking place 
in American agriculture. An enormous expansion of the area of 
land in farms has occurred as our agricultural frontier moved west- 
ward, and this continued expansion of the area in farms, improved 
land in farms, and land in crops has led most of us to believe that 
the increased volume of production was solely a result of the ex- 
pansion in the crop area. (Fig. 1.) 
TREND IN THE USE OF LAND AREA FOR CROPS, PASTURE, 
AND FOREST; UNITED STATES, 1880-1925 
NAN 
QMAy S 
800 S ras ales Sa 
ROI 
400 
Yj y Y 
©1880 1890 1900 1910 1920 1925 
Fic. 1.—The area of land in harvested crops steadily increased up to 1920 at the expense 
of forest and cut-over land on one hand and of pasture on the other hand. During 
the war period the expansion of the crop area was mostly at the expense of improved 
pasture. The 1925 census revealed a contraction of 19,000,000 acres in the harvested- 
crop area as compared with 1920 
However, a consideration of the trend in the acre yields of our 
important food and feed crops will show that a not inconsiderable 
increase in the volume of production of those crops resulted from 
the gradual rise in acre-yields. 
Table 1* and Figure 2 show the trend in yield per acre in the 
United States from 1885 to date for corn, wheat, oats, and potatoes. 
8 These averages are based on the actual annual yields taken | as a 5-year moving 
average centered on the middle year. For actual annual yields, 1883-1925, see Appendix, 
Table I. 
