14 SURFACE- AND SUB-IRRIGATION 



In one of the late issues of a prominent horticultural paper 

 the writer says, " In determining the depth at which the tile 

 should be laid, * * * at no place should the tiles be so 

 near the surface, that they will be disturbed by the plow." We 

 can see that this is true, perhaps, of some soils but it is not 

 true in all cases. 



Since we found that sub-irrigation could not be depended 

 upon as an economizer of water on account of seepage, and 

 since in surface irrigation there is a great loss of water through 

 evaporation, w r e could see no reason why the use of the tiles 

 could not combine the good points of both methods by placing 

 them near the surface. The objection to their being placed 

 above the reach of the plow would be overcome by the fact that 

 they could easily be removed, if necessary, when the crop was 

 harvested. Accordingly, experiments to test this arrangement 

 were carried on at the West Virginia Station the past two years 

 with satisfactory results. 



As this new method of irrigation contains all the commend- 

 able points of both surface irrigation and sub-irrigation, I deem 

 it worthy of consideration. It approaches much nearer an ideal 

 system for economizing water, — doing away with the great loss 

 by evaporation in surface irrigation and by seepage in sub- 

 irrigation. Also, since the tiles are above the greater mass of 

 the roots, the water that does soak away is at the command of 

 the plants. 



SURFACE IRRIGATION 



Where plenty of water is available we believe the best and 

 most satisfactory results are secured by applying the water 

 where needed through ditches. The ditches are easily and 

 quickly made with plow, cultivator, or hoe ; they cost only the 

 time of making, are easily checked at any point, and the opera- 

 tions are under known and visible conditions. There is no 

 obstruction either below or above ground to hinder cultiva- 

 tion ; there are neither pipes nor tiles to be stopped or clogged 

 by roots or foreign matter. While more or less evaporation is 

 going on, this is easily overcome to a certain degree by judi- 

 ciously cultivating and applying the water during the cloudy 

 portions of the day or in the evening. What water does enter 



