IRRIGATION OF CEREALS 



261 



tion of good crops of corn. The longer growing season of 

 corn makes necessary more irrigations and possibly a 

 larger quantity of water than for wheat. Where the rain- 

 fall is less than 12 inches, or on unfavorable soils, or under 

 conditions of very high evaporation, it may be necessary 

 to increase this quantity of water to 18 inches. It is more 

 likely, however, that on deep soils, properly cultivated, 

 the depth of water necessary to produce proper crops of 

 corn may be reduced to 10 or even 7J/2 inches of water. 



If it be assumed that the length of the irrigating sea- 

 son for corn is ninety days, the duty *of a second-foot 

 should not be greatly different from that of wheat. One 



Com 



X 



20 



mnm 



1 1 1 



FIG. 65. Yield vs. water (corn). 



