

SPRAY IRRIGATION. On: 
SHort-Post Type. 
If short posts are used they are set in the ground 2 to 24 feet and 
cut off 1 to 3 feet above the surface. They are spaced 18 to 20 feet 
apart and the nozzle line placed on top between nails or in roller 
bearings. <A 4 by 4 inch post serves well for this type, but should be 
treated as are tall posts. This construction is the least expensive, 
but may cause a somewhat closer spacing of nozzle lines if a low 
hydraulic pressure is to be used. This type also is somewhat in the 
_ way of cultivation and is not efficient for tall-growing crops. When 
nozzle lines are made portable on short posts, posts may be made of 

Fic. 13.—Overhead spray nozzle lines mounted on wooden posts 6% feet above the 
ground. [Farm of Granville W. Leeds, Rancocas, N. J.] 
$-inch pipe sharpened and fastened to the nozzle line so that sup- 
ports are moved with the pipe. 
HicH Posts AND CABLE-SUSPENSION TYPE. 
Where high posts and cable suspension is used the posts are spaced 
from 100 to 200 feet apart and the nozzle line suspended from a tight 
eable or wire strand which takes the form of a catenary curve be- 
tween posts (fig. 14). Telephone poles 8 to 10 inches at the base and 
6 to 8: inches at the top can be used. A length of 24-inch steel pipe 
which may be filled with concrete makes a more substantial post. 


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