Irrigation and Drainage 127 



yield of beets is greater under irrigation than where water 

 is not supplied. This is probably because irrigation makes 

 possible the maintaining of a more desirable moisture- 



.>^^^^^^^'^^?^r^!rt 



Fio. 13. — Reservoir for irrigation water, and diversion dam. 



content in the soil than can be relied on from the rainfall 

 alone. 



Sugar-beet culture is adapted to intensive farming on ac- 

 count of the great amount of man-labor that must be spent 

 on each acre in thinning and harvesting. This condition 

 fits well into the small farms of the irrigated district. 



Sources of irrigation water. 



The most common and least expensive source of water 

 for irrigation is found in running streams. A suitable dam 

 is placed across the bed of the stream to turn water into 

 the canal which carries it to the land to be served. The 



