45 



the amount of Avater applied, and can only be decreased by increasing 

 the flow of water handled l)y one man. 



Ow4ng to the interruption of other work, when a numi)er of men 

 must be assembled every hour t)r so to change the water, it is usually 

 nuich better to arrange the distribution so that one man can use his 

 entire time to good advantage. For instance, one farmer uses several 

 bars of f-inch pipe 34 feet long, provided with three sprinklers each 

 which one man can handle easily. Better work is likeh' to be done 

 where one man devotes his whole time to irrigation. "WTiere the water 

 su])ply is not sufficient to require the entire time of one man, it would 

 be well to arrange the sj'stem so that one man can do all the work 

 when irrigation is required. 



The reason for the prevalence in the East of tlie s)>rinkling metliod 

 of irrigation, which is practicallv unknown in arid sections, lies in two 

 important differences in the conditions of irrigation practice. First, 

 the quantity of water applied in one irrigation in the East nuist be 

 small, owing to the risk of sudden and heavy rains which would swamp 

 a crop if falling soon after a heavy irrigation; and, second, the soils 

 used for truck farming in the East are not, as a rule, so capal)le of stor- 

 ing and retaining water as the arid soils, so that a heavy irrigation once 

 a month will not answer the needs of garden crops in the East. With 

 the sprinkling system it is possible to apply uniforndy as small a quan- 

 tity of water as desired, while with furrows enough must be a])plied to 

 run through the furrows and soak laterally to the roots of the plants. 



In brief, the advantages of the sprinkling system are tliat there is no 

 loss of space if the main pipes are laid underground, and no loss 

 from leakage ; it is applicable to uneven ground and hillsides, since 

 water is delivered under pressure; no special preparation of the sur- 

 face is required, and plants may be set as close as desired; a very 

 small flow of water may be utilized, and a light irrigation maybe 

 very quickly applied in emergency. Its disadvantages are the great 

 tu"st cost for pipe and connections; the high pressure head wliich 

 must be overcome when water is pumped; the excessive cost of city 

 water where used; and the great expense of applying water and 

 maintaining an elaborate system. 



The advantages of the furrow system are its cheapness and simplic- 

 ity, requiring onl^" ordinary farm tools to lay out: the ease with which 

 one man can handle a large stream of w^ater; the fact that water is 

 applied by gravity and need not be pumped higher than the land to be 

 watered, dispensing with high storage tanks. Water may be applied at 

 any time of day without danger of scalding the plants, since the foliage 

 is not wet and evaporation from the ground surface is reduced to a 

 minimum. The disadvantages are: The loss of space where head 

 laterals are used, and the expense of piping, where pipes are used 

 instead of open-head ditches; the cost of leveling and smoothing land 



