THE WATER OF SOILS. 245 



the proper exercise of the root-functions, and that the roots 

 existing there are either inactive or diseased. That in such 

 cases frequent irrigation and abundant fertilization alone can 

 maintain an orchard in bearing condition, is a matter of 

 course; and there can be no question that a great deal of the 

 constant cry for the fertilization of orchards in the irrigated 

 sections is due quite as much to the shallowness of rooting 

 induced by over-irrigation, as to any really necessary exhaus- 

 tion of the land. When the roots are induced to come to and 

 remain at the surface, within a surface layer of eighteen to 

 twenty inches, it naturally becomes necessary to feed these 

 roots abundantly, both with moisture and with plant-food. 

 This has, as naturally, led to an overestimate of the require- 

 ments of the trees in both respects. Had deep rooting been 

 encouraged at first in the deep soils of the southern " citrus 

 belt," instead of over-stimulating the growth by surface fer- 

 tilization and frequent irrigation, some delay in bearing would 

 have been compensated for by less of current outlay for fer- 

 tilizers, and less liability to injury from frequently unavoid- 

 able delay, or from inadequacy, of irrigation. 



Irrigation bv Underground Pipes. Where economy in the 

 use of irrigation water is a pressing requirement, its distribu- 

 tion through underground pipes affords the surest mode of 

 accomplishing that end, in connection with the application of 

 the water in accordance with the principles just discussed. 

 The enormous saving of water effected by its conveyance in 

 cement-lined ditches or concrete pipes, as compared with earth 

 ditches, if additionally combined with its application to in- 

 dividual trees or vines, presents the maximum of economy 

 that can be effected. The actual use of this method is unfor- 

 tunately limited in practice by the high first cost of piping; 

 but as its use renders unnecessary the digging of basins and 

 plowing of furrows and their subsequent closing-up, it is when 

 once established by far the cheapest system, both as to the use 

 of water and of labor. 



The best results of this system are undoubtedly achieved by the 

 use of iron pipes for the distribution in field and orchard, whatever may 

 be the material used for the main conduits. The use of concrete and 

 tile in small sizes proves in the end very expensive, because of frequent 



