42 Practical Farming 



over the rim to the ground through the capillarity set up 

 in the fine meshes of the towel. The same capillarity 

 occurs in the soil when left at rest, and in this rising water 

 there is also brought to the surface soil much plant food 

 that otherwise would be out of reach of the roots of crops. 

 It has been shown that when a glass tube of very small 

 diameter is inserted in water the water will rise in the tube 

 above the surface of the surrounding liquid, and also that 

 the smaller the diameter of the tube is the higher the 

 water will rise within it. In like manner very small tubes 

 form in the soil by which water rises in the same manner, 

 and the extreme fineness of these naturally formed tubes 

 greatly increases the power to draw up the water, though 

 in a far more irregular shape than the straight tube of 

 glass. Professor King says that he ''found that a very 

 fine sand did Uft water through four feet at the rate of 

 .91 pounds per square foot in twenty-four hours, while a 

 clay loam lifted it at the rate of .9 pounds per square 

 foot through the same distance in the same time." By 

 this means water from below is continually being brought 

 within the reach of the plant roots. 



Since all plant food must be in a state of solution in the 

 soil before plants can use it, the importance of a supply of 

 water along with an abundant supply of the oxygen of the 

 air in the soil, will be at once apparent. The fihns of 

 water surrounding every soil particle exert a wonderful 

 influence in the solution of food for the plant roots. Even 

 materials which the chemist finds insoluble in water in 

 the laboratory are slowly attacked by the soil water with 

 its carbonic acid and brought into shape for plants to use. 

 Finely pulverized phosphatic rock when placed in the soil 



