70 PREPARATION OF LAND FOR CORN 



(p. 67), it is drilled. The soil can all be thrown back to the corn in 

 cultivating, covering weeds and finally leaving the land level. 



Furrow openers, consisting of a pair of disks, are now put on 

 regular two-row surface planters. These open a shallow furrow, and 

 the corn may be either drilled or checked. 



FIG. 27. Wheat plants illustrating the principle that permanent roots always develop 

 at about the same depth, whether the seed is planted deep or shallow. 



Yield of Hill and Drill Planting. At the Illinois Station the 

 two methods of distributing seed were compared in this way : Corn 

 was planted one plant every 12 inches, two plants every 24 inches, 

 three plants every 36 inches, and four plants every 48 inches. No 

 marked difference was found in yield of grain per acre, so long as 

 the number of plants per acre was the same. 



