12 BULLETIN 1458, U. S. DEPARTMENT OF AGRICULTURE 
From similar causes the agricultural revolution in northwestern 
Europe entered on its second period of development; but in Ger- 
many and France especially, for various political and economic 
reasons, the developments of this second period came much later 
in the century. Among the causes of retardation Doctor Marbut 
cites the conservatism of the German farmers as a factor explaining 
the slower and deferred adoption of the new scientific methods 
(7, par l6) 
TREND OF CROP YIELDS IN EUROPE DURING THE RECENT PERIOD 
The effects of the widespread adoption of improved scientific 
methods during recent years and the increasing use of commercial 
WHEAT: YIELD PER ACRE 
5-YEAR MOVING AVERAGE FOR VARIOUS EUROPEAN COUNTRIES 
1880-1923 
BUSHELS 
40 
30 
QE) pe ea France 
on? y 
ho aFtrem 
20 aE, i eet ones ST oo! Sl ses as 
Lo) [Reiss Pecc0e, oo ceeee® Peete”? New 
Hungary Russia 
eo 
1880 +1885 1890 1895 1900 1905 1910 1915 1920 1925 
Fig, 5.—There was a general upward trend in the acre-yields of wheat in the various 
European countries during the last half century. It was not until immediately previous 
to the outbreak of the World War that Germany attained wheat yields comparable 
to those of England and Wales. War-time conditions caused a sharp fall in wheat 
yields in both France and Germany. In the former recovery has already taken place 
and in the latter wheat yields are again trending upward 
fertilizers are apparent in the trend of crop yields. The record of 
wheat yields in the various European countries during the last 40 
or 50 years (fig. 5 and Table 3) shows the great changes that have 
occurred.° ‘The moving averages of wheat yields per acre for all of 
these countries display generally rising trends. Similar increases 
occurred in the case of the other cereals and root crops. 
In England and Wales the rising trend of wheat yields continued 
but at a considerably slackened rate, until at about the beginning of 
the present century a level of 31 or 32 bushels per acre was reached. 
During the last 20 years yields have been practically stationary. 
®See Appendix, Table VI, for actual annual yields, 
fee 
