160 JoiHXAL OF THE DEPARTMENT OF AGRICULTURE. AuG., 1922. 



such as the nitrate essential to plants is reduced to injurious nitrite, 

 and others such as ferrous compounds are formed from the non-injuri- 

 ous ferric compounds. It is no wonder then that excessive quanti- 

 ties of water frequently result in a falling off in yield. 



Table I . 



Vield uf Crops icith Different Quantities of Water. 



Table II. 



Yield of Crop in Dry Matter from 30 ineltes of Water applied to ONE 

 ACRE and from 30 inches applied to FOUR ACRES at the rate 

 of 7.5 inches per acre in latter. 



Kinrl (if Crop. 



Thirty Indies spread over 



One Acre. 



P'our Acres. 



Ratio. 



Quantity of Water and Crop Composition. — It has heen found 

 that the quantity of water used has an ajjpreciable eft'ect on the crop 

 composition, and may be summarized as follows: — Large quantities 

 of water bring about an increase generally in the ash, carbohydrate, 

 and fibre. With smaller quantities of water protein percentage in- 

 creases and there is a greater proportion of grain to straw, while the 

 flavour and cooking qualities of crops like potatoes are improved. 

 When we reflect on the many advantages to be derived from a 

 judicious use of irrigation water it is hard to believe that the farming 

 public is so poorly informed that the use of large quantities of water 

 in irrigation is the rule and not the exception. I have yet made no 

 special reference to the damage done to land by alkali or brak formed 

 because of the improper use of water. 



