MANAGEMENT OF THE SOIL 



25 



ful in lightening and loosening the soil after it has 

 been compacted by heavy rains. An objection to 

 their use, under some circumstances, is that they 

 tend to throw buried grass and weeds to the surface. 

 At other times this is an advantage. These harrows 

 can be used successfully on rough, rocky, and stumpy 

 ground, since when one of the limber teeth encoun- 

 ters an obstruction, it straightens out and slips over 



Disk Harrow. 



it, and then springs back into shape. These im- 

 plements are made either as riding or walking 

 harrows. 



Disk harrows are similar in principle to disk 

 plows, but the disks are smaller, usually twelve to 

 sixteen inches in diameter, and a number of them 

 are mounted side and side on one axle. In the 

 usual form of the implement two such gangs of from 

 four to eight disks each are mounted so that they 



