92 ELE^fENTS OF AGRICULTURE 



natural drainage is not sufficient, artificial drainage has 

 to be resorted to. 



Much of the sandy land on the Atlantic coast is too 

 well drained. The soil is so open that truck growers often 

 say that the rain falls faster after it strikes the soil than 

 it did in the air. This region also contains the other ex- 

 treme of marshes that are useless because too wet. Most 

 farm lands lie between these extremes. There are some 

 farms that need a complete system of tile drains 1 placed 

 30 to 1(X) feet apart. But for each farm that needs so com- 

 plete a system of drainage there are many that need par- 

 tial drainage. Probably the majority of farms east of the 

 Missouri river have one or more wet places that would 

 be improved by tile drainage or surface ditches. The 

 necessity for drainage depends much on the crop to be 

 raised. Hay and pasture may do well on land that is so 

 wet as to ruin corn and potatoes. 



98. Effects of Tile Drainage During Drought. At first 

 thought, we should expect that tile drainage would make 

 the land drier during a dry time, and so cause plants 

 to suffer from drought. As a matter of fact, exactly the 

 opposite occurs. Tile drains remove the excess of 

 water during periods of rainfall, so that the plant roots 

 deeply. The roots are then deep enough to endure a con- 

 siderable drought. The roots will actually be in more 

 moist soil as a result of the drains, and will have a much 

 larger amount of soil from which to draw water. The 

 shallow-rooted plants in undrained soil are the first to 

 suffer from drought. 



'Tiles are hollow tubes about a foot long. They are made of clay and 

 are burned like brick. They are laid end to end about two to four feet below 

 the surface of the ground. 



