118 



AGRICULTURAL ENGINEERING 



Dr. Elwood Meade furnishes the following table as the 

 duty of water for different crops in the United States : 



Depth of water used for different crops and the irrigation season for each. 



Crop 



Depth of Irrigation. 

 Feet 



Irrigating season 



Potatoes 



Alfalfa 



Orchard 



Wheat 



Sugar beets 



Oats 



Barley 



Corn 



3.94 

 3.39 

 2.76 

 2.68 

 2.15 

 1.73 

 1.49 

 1.40 



May 17, to Sept. 15 

 April 1, to Sept. 22 

 April 15, to Sept. 2 

 April 1, to July 26 

 July 13, to Aug. 17 

 May 22, to Aug. 20 

 June 12, to Aug. 1 

 July 24, to July 29 



Crops Grown by Irrigation. Most farm crops can be 

 grown successfully by irrigation methods, and no attempt 

 will be made here to discuss all. It is desirable, however, 

 to discuss some of the chief crops grown in this way. 



Grain. One of the principal crops grown by irrigation is 

 grain, and it is one which adapts itself well to irrigation 

 methods. When land is brought under irrigation, grain is 

 usually one of the first crops to be grown. There are several 

 reasons for this. Cereals are food crops and are always in 

 demand. They do especially well on virgin soil and they 

 require the least output in preparing the land. Furthermore, 

 grain is an excellent crop to prepare the land for other crops 

 to follow later. 



In most localities there is enough moisture in the soil to 

 start the grain at the beginning of the growing season, and the 

 number of times that irrigation water must be applied will 

 depend upon the factors which have been described. In 

 some localities along the Pacific coast and in New Mexico 

 and Arizona it may be necessary to apply irrigation water 

 during the winter or nongrowing season. In other localities 



