318 RURAL CALIFORNIA 



rigated alfalfa-growing valleys of the interior; also 

 that the city milk supply, both of San Francisco 

 and Los Angeles, is drawn from irrigated districts 

 and is of such quality that it may stand some irriga- 

 tion after transportation and still meet metropoli- 

 tan standards. All this demonstrates that investment 

 for irrigation is like other investments for the im- 

 provement of land, and governed by the same eco- 

 nomic laws. Irrigation is in exactly the category with 

 fertilization and drainage from the point of view of 

 greater quantity and higher quality of products when- 

 ever either of them is required for that end. 



The United States Census of 1920 summarizes the 

 irrigation achievements of California as follows: 



Acreage in irrigation enterprises 7,204,366 



Acreage irrigated in 1919 4,095,247 



Acreage which enterprises were capable 



of irrigating 5,486,929 



These acreages were 31.2 per cent, 43.7 per cent 

 and 51.6 per cent respectively greater than in 1910, 

 showing that the practice of irrigation has increased 

 more than one-half during the last decade. 



Concerning the capability of the State for irriga- 

 tion development and the relation thereof to the 

 extension of production, Frank Adams of the Uni- 

 versity of California, also connected with the irriga- 

 tion investigations of the United States Department 

 of Agriculture, makes this statement: 



"In at least 65 per cent of the 22,000,000 acres 

 that make up the valleys, agricultural plains and 

 foothills of California, intensive agriculture, if pos- 



