50 



Elementary Principles of Agriculture 



illustrates the appearance of the roots of a corn plant 

 at silking time. 



81. Shall Crops be Tilled Deep or Shallow? It is im- 

 portant that we know the distribution of the roots in 

 the soils that are cultivated with plows; otherwise we 

 might plow too deep and destroy many roots. At one 

 of the agricultural experiment stations it was found 

 that thirty days after planting corn, at the second 





Fig. 32. An illustration of the root-growth of a corn plant at silking time. 

 After Hartley. United States Department of Agriculture. 



cultivation, the roots from the adjacent hills (three feet 

 apart) had already met. A few roots had reached a 

 depth of twelve inches, but the bulk of the roots were 

 within eight inches of the surface. Six inches from 

 the hill, the main roots were within two or three inches 

 of the surface. Midway between the drills they lay 

 within four inches of the surface. Deep plowing at this 

 time with shovel-pointed plows would certainly have 

 injured many roots. 



