90 



FOR BETTER CROPS IN THE SOUTH 



production of early crops, two weeks' gain at this season often 

 means the difference between a bumper crop and a poor one. 



Tile drainage raises the temperature of the soil by removing 

 drainage water which otherwise would have to be evaporated 

 from the surface. Ordinary clay soil contains from 40 to 65 per 

 cent of voids or air spaces; black loam, 40 to 50 per cent; and 

 sandy loam, 35 to 40 per cent. If the soil is saturated with 

 water, these voids are full. Then in a saturated cubic foot of 

 clay soil there would be practically 50 per cent water or at least 

 thirty pounds of water. The same would be true in relative 



Tools used in tiling 



proportions with the other types of soil. It has been found by 

 experiment that removing one pound of water by evaporation 

 lowers the temperature of the soil 10.3 degrees. It is easy to 

 see that where the soil is saturated the temperature would 

 remain low considerably longer than if the drainage water were 

 removed by tiling or underdrainage instead of by evaporation. 



Facilitates Aeration— Air plays an important part in crop 

 production. In fact, many soils, have been found to be practi- 

 cally unproductive until properly aerated. The presence of air 

 encourages the roots to penetrate into the subsoil, through 



