58 ARID AGRICULTURE. 



out large air spaces at bottom of the furrows may 

 be packed to advantage. Loose loam soils that 

 overlie a sub-soil which contains considerable 

 moisture may be packed to bring the particles 

 close enough -together to lift the moisture from 

 below by increased capillary action. The sur- 

 face soil may sometimes be packed to either 

 warm it or get rid of surplus moisture. Where 

 good results follow packing, it should not be neg- 

 lected for it may mean success. Many Western 

 soils, especially those containing much granite, 

 sand or gypsum and lime naturally become com- 

 pacted very soon after plowing. Such soils may 

 be so hard that the attempt to Jceep them prop- 

 erly loosened up is more important than trying 

 to maJce them more compact. 



USE OF THE Rolling soil warms it. There are cold, damp 



HOLLER so j} s w hich may be rolled at times with advan- 



tage. It is usually better to use a corrugated 

 roller in the West, because it leaves the surface 

 rough and there is less drying out or drifting by 

 winds. The smooth roller on young grain will 

 sometimes bring up the moisture and cause the 

 soil to absorb enough warmth to prevent injury 

 by cold. The roller is not an essential farm im- 

 plement on Western farms. 



THE The subsurface packer, recommended for 



arid soils, consists of a series of wedge-shaped 

 wheels, about eighteen inches in diameter, and 



