CHAPTER II 



Influence of Water 



WATER is the greatest single factor in plant growth. 

 It seldom rains at just exactly the right time for its 

 use. The task is to keep this moisture where it can be uti- 

 lized by the growing plants just as rapidly as they need 

 it. Before this can be done successfully one must have a 

 knowledge of the characteristics of the different types 

 of soils, their capacity for holding moisture and the 

 rapidity with which it percolates and evaporates, also 

 the things that are necessary to permit moisture to sink 

 into the ground and keep it from escaping. 



Water is the solvent of mineral elements in the soil 

 which nourish the plant, and since plants can absorb 

 mineral salts only in solution, water is absolutely nec- 

 essary to enable the plant to take nourishment from the 

 soil. 



Water is the means whereby plant food elements are 

 transformed into plant food because without it there 

 can be no chemical action or reaction to transform the 

 elements into plant food. Water also holds in solution 

 food for the plant, carries it from the hair roots to the 

 stem, and from the stem to the places where growth is 

 taking place, transports plant food from one place to 

 another in the soil, and is a temperature regulator for 

 the soil. 



From 75% to 90% of the fresh substance in crops is 

 water, thus water in itself is plant food and essential to 



