98 DRY-FARMING 



the somewhat hard, sun-baked soils, and the numer- 

 ous drainage channels, formed by successive tor- 

 rents, combine to furnish the rains with an easy 

 escape into the torrential rivers. Persons familiar 

 with arid conditions know how quickly the narrow 

 box canons, which often drain thousands of square 

 mi^es, are filled with roaring water after a compara- 

 tively light rainfall. 



The run-off 



The proper cultivation (_)f the soil diminishes very 

 greatly the loss due to run-off, but even on such soils 

 the proportion may often be verj^ great. Farrel 

 observed at one of the Utah stations that during a 

 torrential rain — 2.6 inches in 4 hours — the surface 

 of the summer fallowed plats was packed so solid 

 that only one fourth inch, or less than one tenth of 

 the whole amount, soaked into the soil, while on a 

 neighboring stubble field, which offered greater 

 hindrance to the run-off, l\ inches or about 60 per 

 cent were absorbed. 



It is not possible under any condition to prevent 

 the run-off altogether, although it can usually be 

 reduced exceedingly. It is a common dry-farm 

 custom to plow along the slopes of the farm instead 

 of plowing up and down them. When this is done, 

 the water which runs down the slopes is caught by 

 the succession of furrows and in that way the run- 

 off is diminished. During the fallow season the disk 



