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 700 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 someAvhat 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 li| 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 



