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FUNDAMENTALS OF AGRICULTURE. 



used for plowing tame grass sods have a shorter curved 

 moldboard than those used for plowing wild grass sods ; 

 and plows used for plowing old ground and stubble 

 have a very short, abrupt moldboard. 



Disk Plows handle the soil much as do moldboard 

 plows, but with a rolling instead of a sliding motion. 

 Generally they will work in ground which is too dry 

 and hard or too sticky for moldboard plows; but, as 



TWENTY-HORSE-POWER TRACTION GASOLINE ENGINE DRAWING FIVE 

 FOURTEEN-INCH PLOWS. 



has been determined, the draft of the two classes of 

 plows is about the same. 



Riding Plows. If the fields are not too small, rid- 

 ing plows if properly adjusted pull as easily as walk- 

 ing plows, do better work, and the operator has the 

 advantage of riding. 



Harrows. After the ground has been plowed its 

 surface must be smoothed, so that the seeders will do 

 better work and evaporation will be diminished by 

 causing less surface to be exposed to the sun's rays. 

 Harrows are the tools utilized to smooth the surface 

 of the plowed fields, and are classified as follows: the 



