JVIANAGEMENT OF THE SOIL 



27 



to hold moisture better. If, liowever, a heavy rain 

 has fallen and the land is much compacted, it may 

 be necessary to re-disk it, or to dig it up with the 

 spring tooth. 



Rolling and Dragging. — A roller is a heavy cyl- 

 inder mounted so that it can be rolled over the land. 

 It is used for crushing clods and also for compact- 

 ing the soil when it has been left too loose and open 

 by the plow. It requires good judgment to know 

 when a roller can be profitably used. If harrowing 

 has been properly done, there will be no large clods 



A Roller. 



to crush, and the roller is simply used for firming 

 and compacting the soil. In some kinds of soil if 

 no rain falls for a considerable period after plowing, 

 there is danger that all of the plowed soil may dry 

 out since the air spaces are too large for the mois- 

 ture to rise from below by capillarity. Seeds 

 planted under these conditions would fail to germi- 

 nate. Passing a heavy roller over such a field soon 

 after it was plowed would press the particles closer 



