ALFALFA, FORAGE CROPS AND PASTURES 275 



in the irrigation water for the harvest of cured alfalfa hay, 

 for each inch of irrigation water fell from 1,500 pounds 

 when 6 inches of water were used, to 400 pounds when 36 

 inches of water were used. The maximum yield did not 

 coincide with the economic yield. The results obtained 

 by Fortier have been corroborated by the Utah Sta- 

 tion. Some of the data obtained are found hi the follow- 

 ing table: 



YIELDS OF CURED ALFALFA HAY WITH VARYING QUANTITIES OF 

 IRRIGATION WATER 



The irrigation water applied was increased from 10 to 

 50 inches, and the yield of cured alfalfa hay increased 

 from 9,800 to 10,800 pounds. That is, the yield of cured 

 alfalfa for each inch of water fell from 988 pounds to 216 

 pounds as the irrigation water was increased five-fold. 

 Bark, working in Idaho, found the same law to hold. 

 (Fig. 70.) 



While alfalfa does not respond proportionally to the 

 application of large quantities of water, yet it can endure 

 fairly large irrigations, providing the soil is fertile and not 

 too heavy. In water-logged soils, the yield of alfalfa is 

 invariably lessened. Alfalfa, not properly cared for by 

 harrowing or disking, does not respond well in its yield to 

 the water used. This is particularly important in districts 



