55 



process the weeds arc cut and make mulch, which prevents the soil 

 from baking. The tops of the spindling- alfalfa stems are likewise cut, 

 which causes it to stool out and thicken. 



In alfalfa fields the laterals should be located with an engineer's level 

 or bv somt' o-ood substitute. The gi-ad(> may vary fi-om 0."2 to 0.3 foot 



Alfalfa field, showing location of laterals. 



per 100 feet, and the laterals may be spaced 75 to 125 feet apart. 

 For a permanent crop of this character it also pays to construct 

 wooden checks and division boxes in the supply ditches. When it is 

 found necessary to divide an irrigation stream into two or three smaller 

 heads a division box is convenient. The cost of a box of this kind is 



