CHAPTER IV 

 GENERAL DRAINAGE INFORMATION 



DRAINAGE may be defined as any artificial means by 

 which the removal of surface or ground water is hastened. 



Need for drainage is indicated when water stands at 

 or near the surface of the soil sufficiently long (1) to 

 interfere with farm operations in the way of tillage, plant- 

 ing or harvesting, or (2) to render the soil soggy or compact. 



A discussion is hardly necessary to enforce the impor- 

 tance of performing every operation on the farm with 

 promptness and dispatch. If the reader has followed 

 carefully the discussion of the relation of water to agricul- 

 ture, as set forth on the previous pages, he will understand 

 why soggy or compact soils are undesirable. 



99. Lands requiring drainage. Lands most likely to 

 require drainage fall under one or more of the following 

 heads : 



1. Low-lying flat areas, and especially those more or 

 less surrounded by hills. 



2. Higher areas of open soil with comparatively slight 

 slopes and underlaid by rather impervious subsoils. 



3. Heavy clay soils, even though they have apparently 

 considerable natural surface drainage, but more especially 

 when the surface is marked by slight depressions from 

 which the water cannot drain readily. 



4. It frequently happens that in regions generally 

 well drained, there occur small areas underlaid by nearly 



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