160 THE SOILS AND CEOPS OF THE FARM. 



is to plant corn when the leaves of oak trees are as big 

 as a squirrel's ear, is not much at fault. There is 

 fairly good evidence that in the main corn belt there is 

 a period of three or four weeks within which the time 

 of planting does not materially affect the yield. Very 

 early planting, however, has been found to require 

 more cultivation to keep the land free of weeds. 

 Through the niain corn belt from the 10th to the 20th 

 of May is the usual time of planting. Where corn is 

 planted on old sod-land the corn should be planted 

 later to avoid cut worms and allied insects. 



Experiments have shown that there is little differ- 

 ence in the yield, whether the seed is from the butt, 

 middle or tip of the ear. The tip kernels being 

 smaller have less food material to supply the develop- 

 ing plant. Beyond this there seems to be no reason 

 why they should not produce plants which would yield 

 as abundantly as kernels from any other part of the 

 ear. The kernel does not reproduce itself but the ear 

 from which it was taken. In practice it is found bet- 

 ter not to use tip and butt kernels, especially the 

 former, in order that the planting with the ordinary 

 planters may be more regularly done. 



Corn may be planted from one to four inches deep. 

 In exceptionally dry seasons, planting six inches deep 

 has been known to give better results than shallow 

 planting, but usually one iuch deep is better than" 

 deeper so far as the growth of the plant is con- 

 cerned. When planted by machinery it is usually 

 necessary to plant somewhat deeper in order that all 

 the corn may be covered. Hence the desirability of a 

 uniform seed-bed. Where it is the practice to har- 

 row the land after planting the corn, it is probably 



