ALFALFA, FORAGE CROPS AND PASTURES 269 



the alfalfa seriously injured. If such pasturing is not fol- 

 lowed by disking, there may be a great diminution in the 

 value of the field. Occasionally, stock is turned into the 

 field after each cutting. The practice must be wholly 

 abandoned. It is also important that stock be kept off the 

 field soon after an irrigation. The top soil of alfalfa, as of 

 the grains; must be kept in an ideal condition for plant- 

 growth. 



167. Method of irrigating alfalfa. Water may be 

 applied to the alfalfa field either by flooding or furrowing. 

 If water is abundant, flooding is generally the method 

 employed. Check or border irrigation has been used on a 

 large scale with alfalfa fields. 



The border method uses sections of the field, about 15 

 feet wide, of varying width up to 900 feet long. The bor- 

 der levees are about 7 feet wide and 1 foot high, and 

 covered with alfalfa. Water is run down in a large sheet 

 between these levees. The check method completely 

 incloses large fields of alfalfa with levees, into which the 

 water is run until it covers the whole field to a certain 

 depth. In the inter-mountain region, on the smaller 

 fields, where the flooding method is followed, water is 

 applied by the field-ditch method. From the supply 

 ditch, a transverse ditch is run to the field, from which 

 the water is spread over the soil by means of small field 

 furrows that do not interfere materially with the plant 

 or its harvesting. 



Recently the furrow method promises to displace the 

 flooding method for irrigating lucern fields. Where the 

 soil tends to run together, or where it bakes hard after 

 irrigation, the furrow method is especially employed. 

 Where the supply of water is limited, it has been found 

 advisable also to employ the furrow method. In furrowing, 



