DRAINAGE AND GROUND WATER SJJPPLY 207 



275. The real relation of drainage to capillary and 

 ground water. The actual effect of drainage will be to 

 assist to increase both capillary soil water and ground water 

 for reasons that have been discussed in an earlier chapter, 

 but which may be briefly stated as follows : 



The largest exclusion of water from the soil occurs where 

 the soil is improperly drained, with proportionate losses 

 by run-off and fly-off (evaporation). 



Larger absorption of water occurs where soils are properly 

 drained. The cut-off is increased. 



Proper drainage not only brings about a more open struc- 

 ture of the upper soils, but eventually of the lower subsoils 

 as well, so that while the cut-off is greatly increased, a larger 

 percentage of the cut-off will find its way below the tile. 



Better tillage is the natural accompaniment of proper 

 drainage, and absorption (cut-off) is further increased, and 

 evaporation (fly-off) is diminished. 



276. The experience of other countries. In England 

 tile drainage has been practiced since 1764, and is one of 

 the factors placing that country first among the countries 

 of the world in acre yields of cereals. The greatest 

 agricultural countries of continental Europe have been 

 champions of drainage for many years. A lowering water- 

 table is not, at the present time, a matter of alarm with 

 any of them. 



277. Optimism. " The chief cause of the lowering of 

 subsoil water is remediable ... is bound to be remedied. 

 It [the lowering] can be prevented ... it is prevented in 

 every carefully worked garden, on every intensively cul- 

 tivated farm, on every well kept lawn, . . . Each farm 

 should be made to take care of all the water falling on it 

 during the entire year." 1 



1 McGee, Bulletin 92, Bureau of Soils, U. S. Dept. Agric. 



