CHAPTER VII 
STORING WATER IN THE SOIL 
Tue 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 such 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 soil. 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 
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