THE BEST SYSTEM OF IRRIGATION. I/ 



finer soils, whether in clay or of silty formation, the rise is slower, but 

 higher. So that in a few weeks or months, as the case may be, the water 

 attains twice or thrice the hight that it climbs in the former. He con- 

 cludes, upon this point, that ? " consideration of these results points to 

 the superior value, in suitable soils, of sub-irrigation, or irrigation by 

 seepage from below, over all methods of surface application, because it is 

 thus possible to avoid caking the soil and loss by evaporation." 



It may be observed in this connection, and has been already referred 

 to, that broad and deep disintegration of the soil always influences most 

 favorably capillary action. 



Mr. Cole, the author, who has truly led the waters captive, declares 

 that "the methods of surface irrigation, when compared to those of sub- 

 surface, are as fractions to units." 



Says the able author of a book from which quotations have been 

 made (Hon. Geo. P. Marsh), "The readiness with which water not 

 obstructed by impermeable strata diffuses itself through the earth in all 

 directions, shows the importance of keeping up the supply from subterra- 

 nean sources. The deep-lying veins and sheets of water, supplied by 

 infiltration, from often comparatively distant sources, send up moisture 

 by capillary attraction around the roots of vines and trees. Without the 

 help of artificial conduit, or of water carrier, the Thames and the Seine 

 refresh the ornamental trees that shade the thoroughfares of London and 

 Paris, (paved by flagstone and cement almost impervious to water) and 

 beneath the hot and reeking mold of Egypt the Nile sends currents to 

 the extremest borders of its valleys." 



The diffusion of moisture in this way will depend then mainly upon 

 two conditions the supply received or contained in the underlying 

 strata, and the character of the soil operated upon. Two other points 

 closely allied to these are, the storage capacity underneath and the 

 manner of cultivation. 



Now the position has been taken for sub-irrigation for the orchard 

 and garden, without regard to any artificial system for carrying it out. 



The objections we urge to surface irrigation, and " flooding " particu- 

 larly, as commonly applied, are that it is a wasteful, untidy, unskillful 

 and often an unwholesome method of distributing water. That it is 

 objectionable also in rigorous climates, because of its tendency to induce 

 surface rooting, and for the further reason that it is a most effective means 

 of distributing harmful and destructive weeds. Careless surface watering 

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