CHAPTER XVI 

 CEREALS UNDER IRRIGATION 



WHERE the annual rainfall is less than 10 inches, cereal 

 cultivation by dry-farming is not usually profitable. 

 In such localities cereals are sometimes grown by supple- 

 menting the rainfall with applications of water artificially. 

 Irrigation of cereals is done almost entirely in the Western 

 area. Even in this area, however, the proportional acre- 

 age of cereals under irrigation is not large. In line with 

 the rapid development of dry-farming, there has been a 

 segregation of crops that are grown for marketing, those 

 permitting extensive methods being handled under the 

 latter system, and the intensive crops, such as truck 

 crops and fruits, being retained under irrigation. How- 

 ever, as first crops on new land, and as aids to other crops, 

 cereals are still found to have some importance under irri- 

 gation. In 1914 there were grown on the United States 

 Government Reclamation projects alone, 148,517 acres of 

 wheat, oats, barley, and rye. In 1909 the total irrigated 

 acreage of small grains in the United States was 1-^ mil- 

 lion acres. 



446. Clearing and leveling. Cereals are usually 

 irrigated by the method of flooding from field laterals; 

 that is, from field ditches branching off from the main or 

 supply ditch. The land must therefore be leveled or 

 graded into a uniform slope. First it is cleared of the 

 sagebrush and other growth in the manner already de- 



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