Water Requirements 



123 



tiw-- ..->,..... -.,.., ,.-,,,,,-,,.- ... .,fp !i;--'.vv.v!.--!.: .-,-;j^rr'i 



FIG. 39. Rice-field prior to drawing off water for harvesting, 

 Louisiana. 



Fruits, In most sections of the Pacific coast region, 

 deciduous fruits are commonly irrigated when the rainfall 

 is less than twenty inches, and many believe that irriga- 

 tion may be desirable when the precipitation is equal to 

 or somewhat greater than this amount. Citrus fruits 

 grown on a commercial scale in that region are invariably 

 irrigated. In all cases the purpose of irrigation, as Wick- 

 son says, " is a means of soil improvement to be employed, 

 like other means of improvement, when the soil needs 

 it." 



The following tables will suffice to indicate for the two 

 types of fruit mentioned the usual amount of water added 

 by irrigation to supplement the normal precipitation : 



