Sub - Irrigation 



399 



tile could scarcely be less than one line every 5 feet, 

 and it would be necessary to place them at least far 

 enough below the surface not to be disturbed in 

 working the soil in crop rotation. 



Fig. 124. Plan of fields for sub-irrigation experiments. 



At one cent per foot for 3 -inch drain tile, the cost 

 for pipe alone would be $87.12 per acre where the 

 lines are laid 5 feet apart. In addition to this ex- 

 pense, there would be the cost of transportation, 

 breakage, and laying of tile connecting with the head 



