IRRIGATION IN FLORIDA. 41 
position. The sprays when running under a pressure of about 40 
pounds per square inch will each deliver 12 to 15 gallons per minute. 
Each nozzle is allowed to remain in one position about 20 minutes, 
which means an operation of about 80 minutes for each tree, as four 
set-ups of one nozzle usually are required to complete the irrigation 
of one tree. This amounts to about 1 inch of water over the grove. 
The operation of this system requires the work of six men — five in 
the field to move the nozzles and one at the engine. 
The chief objection to this system is that it takes too long to irri- 
gate the entire grove. When the system was completed for one-half 
of the grove three weeks was required to irrigate that portion of it. 
At this rate it would take about six weeks to irrigate the whole 
grove, which is much too slow for any part of Florida, and especially 
for the shallow soils of this section. The time might be shortened 
by night irrigation, but night labor is very hard to obtain. More 
wells and pumping units would permit faster work, and these will 
have to be installed before the plant can be regarded as entirely 
satisfactory, since it is obviously impossible to irrigate successfully 
370 acres with only TOO gallons of water per minute. 
The cost of the plant, exclusive of the wells, is about $35,000, or 
about $100 per acre. This is much lower than could be expected for 
a plant serving a small acreage, and would be somewhat higher, of 
course, if the grove could be irrigated in less time. 
This type of system, as used in a large grapefruit grove near Pal- 
metto, differs only in the spacing of the hydrants, which are 90 feet 
apart instead of 100 feet, and there are many systems similar to this 
all over the citrus section of the State, although the average irrigated 
grove is much smaller, probably amounting to from 10 to 20 acres. A 
wide variation exists also as to the size of laterals and the spacing of 
the hydrants. Many of the groves have a hydrant spacing of 150 feet, 
a 1| or 2 inch hydrant being used, and about 75 to 100 feet of hose. 
The smaller groves, as a rule, are not equipped with the movable 
nozzles, some irrigators simply letting the water run at the foot 
of the tree or directing the spraying of the trees by hand while 
moving from place to place through the grove. 
The great trouble with many of the systems described above is that 
the owners try to economize on size of piping and pumping outfits. 
Some irrigators apply insufficient quantities of water. It is very 
doubtful if the application of small quantities is of any material 
advantage, as the soil often is merely packed, which spoils the dust 
mulch and thus aids evaporation. 
ORCHARD IRRIGATION BY AUTOMATIC-SPRINKLING SYSTEMS. 
The automatic-sprinkling system also is used in orchard irriga- 
tion, both the overhead-pipe and the rotary-nozzle types being 
