



SPRAV-IRRIGATION.O .c.8 ) Us 15 
at least one-half the distance between standpipes, so that the entire 
area can be covered. There are many adjustable nozzles on the 
market which may be screwed to the end of a hose and made to dis- 
charge a solid stream or any degree of spray by manipulation of the 
nozzle parts. There are two familiar designs of nozzles for this pur- 
pose. One must be held in the hand constantly or moved about at 
very short intervals. The other may be set in one ae and al- 
lowed to spray over a circular area. : 
One of the most popular portable spray arrangements is shown in 
figure 8. This consists of a #-inch pipe, 18 to 20 feet long, containing 
a row of small nozzles similar to those used in overhead irrigation 
systems. This pipe has a hose connection at one end and is supported 
on movable tripods or on short posts which are set permanently in 
the ground or attached to the cold frame or hot bed. In some in- 
stances the portable spray line contains three rows of “ mist nozzles ” 
set at about 45° angle with each other and 3 feet apart in the row. 
With this arrangement the pipe can be laid on top of a cold frame 
and a fine mist spray will cover the bed. 
The hose and portable nozzle system of spray irrigation is the 
oldest and least efficient of spray methods. It is impossible to get an 
even application over the entire field or under one position of: the 
nozzle. The constant attendance necessary and the liability of over 
or under irrigation makes the cost of operation high and the results 
dependent upon the skill of the laborer. The greatest field for this 
type of irrigation seems to be indoor spraying, outdoor sod lands, 
seed beds, and small garden plots. The first cost is the smallest of 
any type oa spray irrigation. 3 
STATIONARY-NOZZLE SPRAY SYSTEMS. 
Stationary nozzles fed by underground pressure systems of piping 
(fig. 9) have gained favor in Florida, where the sandy character of 
the soils makes rapid irrigation necessary. This type of equipment is 
being used for the irrigation of truck and citrus groves. Standard 
steel or wrought-iron pipe and fixtures are commonly used, but the 
main feed pipe sometimes is cast iron or riveted steel. Main feed 
pipes are run underground, leading from the water works or pump- 
ing plant into the field. Laterals are placed 12 to 15 inches below the 
surface in parallel lines under the entire field. At intervals of 30 to 
50 feet risers to which the nozzles are attached are placed on the 
lateral lines so that the nozzles are spaced equidistant from each other 
in triangular form, as shown in figure 9. Figure 10 shows an under- 
ground section of a main feed pipe, with connections to laterals. 
Each lateral is controlled by a valve and in some cases a valve is placed 
on each riser, so that a part of the nozzles on a line may be cut off, 



