THE IRRIGATION AGE. 



319 



Nothing could show more conclusively than these figures the 

 necessity of irrigation under the existing conditions, and the enor- 

 mous sugar-equivalent value of irrigation water applied systematically 

 to the cane during the season of maximum growth, which is the sum- 

 mer season. An equal volume of water falling in heavy rains during 

 the cool season, when growth is slow, is largely lost through percola- 

 tion and produce a comparatively small value in sugar. 



The following tables contain a statement of the crops of 1897-98 

 and 1898-99 and of the value of the water applied by irrigation. A 

 brief table is first given showing the average weight of cane and 

 yields of sugar for the two seasons: 



These are the results in cane and sugar per acre of crops that 

 were about nineteen months on the ground and subject to systematic 

 irrigation for seventeen months. 



The relation of the crops to the total volume of water received 

 both as rainfall and by irrigation is as follows: 



WATER REQUIRED TO PRODUCE 1 POUND OF SUGAR. 



The volumes of water consumed by the cane per pound of sugar 

 made during the growth of the two crops are very nearly the same. 

 During the growth of the crop of 1897-98 some of the rainfall occurred 

 in heavy precipitations, and it was ascertained that water escaped 

 through the subsoil and was lost. During the production of the crop 

 of 1898-99 none of the water received, either from rainfall or from 

 irrigation, was lost in this manner. No single rainfall exceeded 1 

 inch, and in irrigating no more than 1 inch of water was applied at 

 any single watering. 



It is seen from the preceding tables that the maximum quantity 

 of water applied artifically during a season of extreme drought was 

 77 inches during a period of seventeen months, or 2,090,858 gallons of 

 water per acre, to make a crop containing 27,133 pounds of pure sugar 



