CHAPTER 11 



LAXD DKAINAGE 

 By Elmer O. Pippin, B.S.A.* 



Evidences of the need for drainage. — Large areas of farm 

 land are too wet for the best growth of croi)s. Land is too wet 

 whenever within the zone of soil in which the roots of crops 

 develop, namely, about three feet of the surface, free water 

 would stand in an excavation. Drainage does not remove useful 

 water from the soil. It removes the injurious surplus water from 

 the soil. Remember that the roots of the usual type of farm 

 crops — corn, wheat, clover, fruit trees and that type of plants 

 — will not live in a soil saturated with stagnant water for more 

 than two or three days, and even that period of submergence 

 weakens the general vitality of the plant. 



This line of observation should suggest to the reader that it 

 is not necessary that Avater stand on the surface of the soil or 

 even in the plow furrow in order that the soil be poorly drained. 

 Roots of most crops penetrate two, three and even four and five 

 feet deep if given an opportunity, and therefore the creation of 

 perfect conditions for crop growth requires that the possibilities 

 of standing water in the soil within a depth of at least two feet 

 should be avoided by artificial drainage if the natural drainage 

 is inadequate for that purpose. 



Other indications of a wet soil, in addition to that soft, mirey 

 character, familiar to all, are severe ''heaving" when it freezes; 

 curled leaves of crops on such areas in dry periods, and areas 

 of weeds such as planton and other plants best able to withstand 

 such conditions. Li addition, the subsoil that is poorly drained 

 has a mottled color and otherwise shows by its appearance that 

 it is inclined to be too wet. The more intensive the type of crop 

 production the more important it is that good drainage should 

 be insured. 



Why land is wet. — Land may be wet from a number of causes. 

 Throughout the eastern half of the United States, and, in fact, 

 wherever the annual rainfall exceeds thirty-five inches, there is 

 more water than crops require or the soil can retain in the film 



* College of Agriculture, Cornell University. 



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