10 BULLETIN 1458, U. S. DEPARTMENT OF AGRICULTURE 
nually with about 7 bushels more of these crops per capita than 
would have been available under the acre-yield level of the base - 
period 1885-1889. 
TREND OF CROP YIELDS IN EUROPEAN AND OTHER FOREIGN 
COUNTRIES 
A mere glance at the present-day statistics of yield per acre of 
crops in the central and northwestern European countries reveals a 
relatively high level of productivity. But many individuals in the 
past, and even at the present, either misconstrue or do not fully 
understand the significance of the higher yields obtained in these 
countries. It is desirable to recognize the danger of unqualified 
comparisons of yields in individual European countries and the 
United States (4, p. 466-7). 
To understand fully the significance of these high yields of the 
present day and the metamorphosis of Kuropean agriculture during 
the last century, the problem must be viewed with the changes 
brought about by the industrial revolution and the accompanying 
increase in Kuropean population as a background. 
It was not until after the Civil War that cheap American grain 
attained importance as a factor to be considered in European agri- 
cultural organization. For some time previous (in the case of 
England almost a century), the increasing demand for food to 
supply the needs of the growing population resulted in rising prices, 
making possible the beginning of the development of the intensive 
type of agriculture in northwestern Europe. 
With only a limited and fairly well-occupied area available, the 
required increase in volume of production could come only from an 
increase in production per acre. The rising level of productivity 
previous to 1870 proceeded without any great complications, owing 
to the fact that cheap American grain was not yet available on 
a large scale. By that time England had already attained practi- 
cally the full development of its “ high farming.” On the continent, 
however, during the last 50 years, especially in Germany, govern- 
ment subsidies stimulated the continued development of intensive 
agricultural methods of production (45, pp. 45-56). 
THE TREND IN YIELDS PER ACRE BEFORE 1880 
From the rather scant data available for the period preceding the 
modern era in Europe it is evident that crop yields were at a very 
low level. In England during the Middle Ages wheat yields ranged 
from 6 to 10 bushels per acre (2, p. 899). On the continent yields 
were probably not any higher. Under the common field system the 
soils had long before the end of the medieval era lost their power to 
produce more than 6 or 8 bushels of wheat per acre. With the aid of 
the fallowing practice farmers were just barely enabled to keep their 
soils in a rough condition of equilibrium on the basis of even these 
small yields. 
The period from the latter half of the eighteenth to the middle 
of the nineteenth centuries marked the beginning of the great changes 
in European agricultural methods. This period has been described 
as the agricultural revolution or renaissance. In brief, it meant the 
