THE WATER NECESSARY FOR A CROP 19 
bushel of wheat, with the corresponding quantity of 
straw, would require 2 times 45,000, or 90,000 
pounds of water. This is equal to 45 tons of water 
for each bushel of wheat. While this is a large fig- 
ure, yet, in many localities, it is undoubtedly well 
within the truth. In comparison with the amounts 
Fic. 8. The famous Palouse wheat section is a succession of low rolling 
hills. Idaho. 
of water that fall upon the land as rain, it does not 
seem extraordinarily large. 
One inch of water over one acre of land weighs 
approximately 226,875 pounds, or over 113 tons. 
If this quantity of water could be stored in the soil 
and used wholly for plant production, it would pro- 
duce, at the rate of 45 tons of water for each bushel, 
about 24 bushels of wheat. With 10 inches of rain- 
