PROPORTION OF GRAIN TO STRAW 261 
of heads to leaves and stems is highest in dry-farm 
crops. Infact, it is a general law that the proportion 
of heads to straw in grain crops increases as the water 
supply decreases. This is shown very well even 
under humid or irrigation conditions when different 
seasons or different applications of irrigation water 
are compared. For instance, Hall quotes from the 
Rothamsted experiments to the effect that in 1879, 
which was a wet year (41 inches), the wheat crop 
yielded 38 pounds of grain for every 100 pounds of 
straw; whereas, in 1893, which was a dry year (23 
inches), the wheat crop yielded 95 pounds of grain to 
every 100 pounds of straw. The Utah station like- 
wise has established the same law under arid condi- 
tions. In one series of experiments it was shown as 
an average of three years’ trial that a field which had 
received 22.5 inches of irrigation water produced a 
wheat crop that gave 67 pounds of grain to every 
100 pounds of straw; while another field which re- 
ceived only 7.5 inches of irrigation water produced a 
crop that gave 100 pounds of grain for every 100 
pounds of straw. Since wheat is grown essentially 
for the grain, such a variation is of tremendous impor- 
tance. The amount of available water affects every 
part of the plant. Thus, as an illustration, Carleton 
states that the per cent of meat in oats grown in Wis- 
consin under humid -conditions was 67.24, while in 
North Dakota, Kansas, and Montana, under arid and 
semiarid conditions, it was 71.51. Similar varia- 
