TYPES OF TILLAGE IMPLEMENTS 



471 



will be thoroughly puddled, and will dry out into a hard 

 lumpy condition. Such a structure requires a considera- 

 ble time to overcome. 



As to the second factor, there are two general types 

 of turning plows: (1) The common moldboard plow. 

 (2) The disc plow. The mode of action of the two is 

 quite different, although, so far as the soil is concerned, 

 the result is much the same. The moldboard plow 

 seems to have a wider application than the disc plow, 

 although both have a particular sphere of usefulness. 



For any given texture of soil and any given soil 

 condition, there is a type of plow, a shape of mold- 



Fig. 131. Types of coulters. Lower right hand, knife coulter; lower left 

 hand, rolling coulter; upper right hand, fin coulter; upper left hand, jointer. 

 The last-named attachment assists in turning trash under the surface as well 

 as to cut the soil. 



