28 AGRICULTURE 



soil and facilitates the entrance of air. Its 

 presence, also, tends to diminish the resistance 

 offered by the soil to the extension of the 

 root range of plants, and to the upward 

 growth of young seedlings. 



Intimately associated with the capacity 

 to retain water is the power that soil, in 

 common with many substances, has to raise 

 water from deeper layers, and to attract it 

 horizontally from one point to another. Did 

 the soil not possess the power of bringing water 

 from the subsoil to the region where plants 

 dispose their roots, our farm and garden 

 crops would seldom be able to survive an 

 ordinary summer. Experiments have shown 

 that many crops in the course of a growing 

 season part with much more water to the air 

 than directly reaches the land during that 

 period in the form of rain, and it is only by 

 tapping underground supplies through the 

 agency of capillarity, that crops are able to 

 grow during weeks and even months of 

 persistent drought. The power possessed by 

 soil of raising water against the force of 

 gravity can be illustrated by taking a lump of 

 dry clay and dipping the lower part into a 

 bowl of water, when it will be seen that a 

 certain amount of the water instantly rises into 

 the clay, which, if held long enough in contact 



