PLANT FEEDING. 31 



4. Now state in tons the total three billion bushel 

 crop of corn and of corn stover, and the tons of plant food 

 contained in each. How many freight cars, each holding 

 20 tons, will be required to haul the corn crop? Of such 

 a train how many cars would be required for the total 

 plant food in the corn, were it all separated from the 

 grain ? 



5. Corn stover is so bulky that 10 tons would make 

 an average carload. How many cars would be required 

 to haul this year's crop of corn stover, and in this train 

 how many cars would be filled with the plant food in the 

 stover, if it all could be separated from the stover? 



Two KINDS OF FARMING. 



Grain farming forces plant food from the soil but the dairy cow maintains the 

 fertility of the land. 



ANSWERS TO ABOVE QUESTIONS. r 



1. From the 10-acre piece of corn the yield is 325 

 bushels of shelled corn, containing of nitrogen 344 

 pounds, of phosphoric acid 130 pounds, of potash 65 

 pounds. The amount of stover produced is 52,052 

 pounds, containing of nitrogen 520+ pounds, of phos- 

 phoric acid 156+ pounds, of potash 728+ pounds. Totals 

 of .corn and stover together, nitrogen 864 pounds, phos- 

 phoric acid 286 pounds, potash 793 pounds. 



2. The total weight of an average American crop of 

 corn stover is 480,500,000,000 pounds. 



