CHAPTER VI 



Irrisation 



The value of water in plant growth can hardly be 

 overestimated. Water is not only a plant food 

 within itself, but all the other elements of plant food 

 must be carried into and through the plant dissolved 

 in water. The upright position of many herbaceous 

 plants and the proper spread of the leaves to the 

 sunlight depend directly upon the cells of the plant 

 being properly filled with water. When sufficient 

 water for this purpose is lacking, the leaves, and in 

 many cases the body of the plant, wilt and droop, 

 as is seen pa,rticularly 

 in case of the corn dur- 

 ing hot, dry periods. 

 Proper amounts of 

 water in the soil are 

 also necessary for the 

 decomposition of or- 

 ganic as well as min- 

 eral materials therein, 

 yet an excessive 

 amount of moisture 

 prevents these changes. The application of water to the 

 soil by artificial means was long considered practical 

 only in the arid and semi-arid regions of the country, 

 where the rainfall during the entire season amounted 

 to perhaps 15 inches or less. It is a well-recognized 

 fact, however, that in almost every portion of the so- 

 called humid regions where the annual rainfall 

 amounts to 40 inches or more there is almost always 



TWO-ROW HORSE CULTIVATOR 



