SOILS AND FERTILIZERS 



95 



in supplying moisture for fruit trees, vegetables, berries, 

 and almost every other kind of product, the advantage 

 being that the water carried by the pipes is discharged 

 directly below the roots of the plants instead of on the 

 surface of the soil. Less water is required because 

 there is no loss by evaporation, but the expense of laying 

 the pipe is great. If the lines of tiles can be laid so that 

 they open out of one ditch and can be readily filled by 

 turning the water into the ditch, the labor cost of irri- 

 gation will be kept at a minimum. 



DRY FARMING 



In the semi-arid regions of the western part of the 

 United States, where the rainfall for the entire year is 

 not sufficient for 

 maturing a crop, a 

 system of cultivat- 

 ing known as dry 

 farming is being 

 practiced. It 

 should not be in- 

 ferred from the 

 name that by this 

 system plants will 

 subsist on smaller 

 quantities of water 

 than in other cases. 

 The system con- 

 sists in Carefully FIG. 35. Subsurface Packer. 



conserving the 



moisture that falls during the entire year by summer 



tillage. During this year the land is not sowed to crops, 



