294 



IRRIGATION PRACTICE 



The sugar beet, like the other crops hitherto studied, 

 is subject to the law that the increased yield due to the 

 increase of irrigation is not proportional to the added 

 quantity of water. Roeding found, as shown in the fol- 

 lowing table, that during the season of 1905-06, on a 

 clayey loam of good depth, as the water was increased 

 from 6 to 18 inches, or three-fold, the yield increased only 

 from approximately ten tons to nearly thirteen tons to 

 the acre. The Utah results, as also shown hi the following 

 table, are practically the same. 



YIELDS OF SUGAR BEETS WITH VARYING QUANTITIES OF 

 IRRIGATION WATER 



Water was applied from 5 inches to 50 inches, or ten- 

 fold. The yield under this treatment increased from 13.8 

 tons to 24.5 tons, or not quite double. Within these 

 limits the yield per inch of irrigation water fell from 2.76 

 to 0.49 tons of sugar beets. (Fig. 77.) 



By understanding this law, the possibility of 30 acre- 

 inches may well be illustrated. If 30 acre-inches are made 

 to cover 1 acre, the yield is 20.82 tons of sugar beets; 2 



