12 



AGRICULTURE FOR BEGINNERS 



The soil is a great storehouse for moisture. After the 

 clouds have emptied their waters into this storehouse, the 

 water of the soil comes to the surface, where it is evapo- 

 rated into the air. The water comes to the surface in just 

 the same way that oil rises in a lamp wick. This rising 

 of the water is called capillarity. . 



It is necessary to understand what is meant by this big 

 word. If into a pan of water you dip a glass tube, the 

 water inside the tube rises above 

 the level of the water in the pan. 

 The smaller the tube the higher 

 will the water rise. The greater 

 rise inside is perhaps due to the fact 

 that the glass attracts the particles 

 of water more than the particles of 

 water attract one another. Now 



FIG. 6. AN ENLARGED a Pl% this principle to the soil. 



The soil particles have small 

 spaces between them, and these 

 spaces act just as the tube does. 

 When the water at the surface is 



carried away by drying winds and warmth, the water deeper 

 in the soil rises through these soil spaces. In this way 

 water is brought from its soil storehouse as plants need it. 

 Of course, when this water reaches the surface, it evap- 

 orates. If we want to keep it for our crops, we must 

 prepare a trap to hold it. Nature has shown us how this 

 can be done. Pick up a plank lying on the ground. Under 

 the plank the soil is wet, while the soil not covered by the 

 plank is dry. Why? Capillarity brought the water to the 

 surface. The plank, however, keeping away wind and 



VIEW OF A SECTION 

 OF MOIST SOIL SHOW- 

 ING AIR SPACES AND 

 SOIL PARTICLES 



