IRRIGATION 267 



majority of irrigation systems a waste of water means an 

 unnecessary outlay. 



Benefits of irrigation. Besides the increase in quantity 

 and quality of the crop produced on irrigated lands, there are 

 numerous other benefits which may attend the use of a sys- 

 tem. Irrigation has been employed extensively for frost 

 protection. Growing crops that are sensitive to a late or 

 early frost can be saved if the water is turned on during the 

 night when there is danger of the temperature dropping to 

 the freezing point. Delicate crops have been saved by the 

 use of water when the temperature fell as low as 27 Fahren- 

 heit for a short period. Cranberry bogs are irrigated by the 

 flooding system for the purpose of retarding early spring 

 blooming, protecting them from frost during the ripening 

 period, and water is permitted to freeze on the bogs during 

 the winter to prevent the vines from being heaved out of the 

 soil by repeated freezing and thawing. Rice fields are flooded 

 to prevent birds from eating the rice seed and to kill weeds. 

 Water, when properly applied, will hasten the ripening period 

 of fruit several days, and the season for propagating by bud- 

 ding can be prolonged, because the water will cause the bark 

 to slip for a longer period. In some localities the sediment 

 carried by the water serves as fertilizer. The fertility of the 

 Nile Valley is attributed to the silt annually deposited by 

 overflowing water. Crops which are transplanted in the 

 fields are greatly benefited by irrigation, since the moisture 

 supply can be controlled to promote rapid growth, maximum 

 yield, and high quality of product. 



BIBLIOGRAPHY 



Anderson, D. H. Primer of Irrigation. D. H. Anderson Publishing 



Co. 

 Etcheverry, Bernard A. Irrigation Practice and Engineering. 



McGraw-Hill. 

 Fortier, Samuel. Use of Water in Irrigation. McGraw-Hill. 

 Mead, Elwood. Irrigation Institutions. Macmillan. 

 Newell, Frederick H. Irrigation in the United States. Crowell. 



