PLANT FEEDING. 29 



(2) One bushel of 56 pounds therefore contains 

 56-100 of the above quantities, which is of nitrogen 

 1.06 pounds, of phosphoric acid 0.4 pounds, of potash 

 0.2 pounds, or a total 1.66 pounds of these elements. 



(3) One ton of shelled corn contains 20 times the 

 quantity in 100 pounds, or a total of nitrogen 38 pounds, 

 of phosphoric acid 14 pounds, of potash 8 pounds. 



(4) A crop of 25 bushels of shelled corn per acre con- 

 tains of nitrogen 26.5 pounds, phosphoric acid 10 pounds, 

 potash 5 pounds, or a total 'weight of these three 

 elements of 41.5 pounds. 



WHY Is THE DIFFERENCE So GREAT? 



The plot at the right has been in corn for many years, while at the left the 

 corn was rotated with clover and oats. This shows that crop rotation and 

 legume crops improve the land. 



(5) Two tons of field-cured corn stover contain of 

 nitrogen 40 pounds, phosphoric acid 12 pounds, potash 

 56 pounds, a total of 108 pounds. 



(6) The 25 bushels of corn and two tons of stover 

 from one acre therefore contain of nitrogen 66.5 pounds, 



