236 THE FIRST BOOK OF FARMING 



presence of more or less free water standing on the 

 surface. 



In some lands the surface water does not appear 

 as free water standing on the surface. In such 

 cases : 



A need of drainage is indicated by the curling 

 and wilting of the leaves of corn and other crops 

 during dry, hot weather. This curling and wilting 

 is due to the fact that during the early growth of 

 the crop free water stands so high in the soil that 

 the crop roots are confined to a shallow layer of 

 soil. When dry, hot weather comes, the free water 

 recedes, the upper soil dries out, and the roots can- 

 not get sufficient water to supply the demands of 

 transpiration, hence the curling and wilting of the 

 leaves. 



If drains are placed in this soil, the free water 

 will be kept at a lower level in the spring and the 

 plant roots will develop deeper in the soil, where 

 there will be constant supply of film water during 

 the dryer and warmer summer weather. 



The wiry and spindling growth of grass and grain 

 crops may indicate too much water. 



The growth of moss on the surface of the ground 

 and the cracking of the soil in dry weather are also 

 indications of too much water. 



DRAINS 



How can we get rid of this surplus free water? 

 We can make passageways through the soil to a 



