iJO THE FIRST BOOK OF FARMING 



Capillary water is the other important form of 

 water in the soil. This is moisture which is drawn 

 by capillary force or soaks into the spaces between 

 the soil particles and covers each particle with a 

 thin film of moisture. 



FILM WATER 



Take a marble or a pebble, dip it into water and 

 notice the thin layer or film of water that clings to 

 it. This is a form of capillary water and is some- 

 times called film water or film moisture. Take a 

 handful of soil that is moist but not wet, notice 

 that it does not wet the hand, and yet there is 

 moisture all through it; each particle is covered 

 with a very thin film of water. 



Now this film water is just the form of water 

 that can supply the very slender root hairs without 

 drowning them, that is, without keeping the air 

 from them. And the plant grower should see to it 

 that the roots of his plants are well supplied with 

 film water and are not drowned by the presence of 

 free water. Capillary water may sometimes com- 

 pletely fill the spaces between the soil particles ; 

 when this occurs the roots are drowned just as in 

 the case of free water as we saw when cuttings 

 were placed in the puddled clay (see Fig. 18). Free 

 water is indirectly of use to the plant because it 

 serves as a supply for capillary and film moisture. 



Now I think we can answer the question which 

 was asked when we were studying the habit of 



