WHERE DRAINAGE WILL HELP 



127 



instances is to allow the roots to penetrate the soil much deeper 

 at all times and thus prevent suffering during the dry season. 



Where an annual overflow of water occurs along streams its 

 prompt removal through some system of drainage is essential to 

 the best production of crops. Most farm crops would be smothered 

 when the water is allowed to stand on the field for many days at a 

 time. Underdrains would prevent much damage. 



There are often areas on mountain sides or hillsides where 

 water from above enters the ground and appears again at the 

 surface or near the surface. The crops may there suffer from too 

 much water, even though the area is much elevated and drainage 

 seems natural (Fig. 83), Such paradoxical cases are frequently 



Fia. 83. Glade land in a mountainous region which was much improved by drainage. 

 After being both drained and limed it is very productive. 



found and are caused by thepeculiar underground formation 

 which brings seepage water toward the surface. This water is 

 not abundant enough in any one stream to be called a spring, but 

 in reality numerous springs cause the condition. The remedy is 

 to place a line of underdrainage along the upper side of the area to 

 gather the seepage water and conduct it away. 



Limited low areas within the boundaries of a single farm are 

 often found where the surrounding high land drains the surface 

 water into them. Usually the soil in such places is very rich. 

 Drainage will permanently improve them by making the soil 

 available for crop use each season. 



Large areas of flat land which may be so set as to be commonly 

 called marshes are often capable of improvement by an extensive 



