LAND DRAINAGE 65 



CHAPTER VII. 

 LAND DRAINAGE. 



All good farm land should be well drained. In some 

 cases it is naturally drained because of the loose or open 

 character of the subsoil. In other places we find the sur- 

 face so sloping that much of the rainfall is carried away on 

 the surface or near the surface. There are special cases 

 where some form of artificial drain should be used. 



What Drainage Does. — In soils where water stands too 

 close to the surface, drainage will help in several ways. We, 

 therefore, use draining ditches or drain pipes for the 

 following reasons: 



1. To remove surplus water. 



2. To admit air to soil and roots. 



3. To deepen feeding area for roots. 



4. To reduce suffering at time of drought. 



5. To aid tillage. 



6. To increase chemical action. 



7. To raise the soil temperature. 



Soil which has been well drained is improved, not only 

 by the removal of water from it, but because the more rapid 

 passage of water through the soil carries the air and warmth 

 to lower levels, which are important factors in making plant- 

 food soluble, and thus increasing the power of plants to 

 secure food. 



On too many farms we find half-developed crops grown 

 year after year upon land which would be able to yield 

 large returns if properly drained. 



Methods of Drainage. — There are two general methods of 

 draining land: first, by open ditches, which may have either 

 straight banks or sloping banks; second, by underdrains or 

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