CHAPTER VII 



STORING WATER IX THE SOIL 



The large amount of water required for the pro- 

 duction of plant substance is taken from the soil by 

 the roots. Leaves and stems do not absorb appre- 

 ciable quantities of water. The scanty rainfall of 

 dry-farm districts or the more abundant precipita- 

 tion of humid regions must, therefore, be made to 

 enter the soil in sueli a manner as to be readily avail- 

 able as soil-moisture to the roots at the right periods 

 of plant growth. 



In humid countries, the rain that falls during the 

 growing season is looked upon, and very properly, as 

 the really effective factor in the production of large 

 crops. The root systems of plants grown under 

 such humid conditions are near the surface, ready 

 to absorb immediately the rains that fall, even if 

 they do not soak deeply into the S(3il. As has been 

 shown in Chapter IV, it is only over a small portion 

 of the dry-farm territory that the bulk of the scanty 

 precipitation occurs during the growing season. 

 Over a large portion of the arid and semiarid region 

 the summers are almost rainless and the bulk of the 

 precipitation comes in the winter, late fall, or early 



94 



