PLANT FEEDING. 7 



on one acre, and won the first prize for the state a trip 

 to Washington. What was the draft upon that acre of 

 soil? 



Average Production Per Acre in the United States. 



Wheat Oats Cotton Corn Timothy Potatoes 



14 bushels 28-6 bushels 1-3 bale 29.4 bushels 1.1 tons 85 bushels 



13. Determine feeding draft on the soil for each of 

 the above crops on the basis of the average produc- 

 tion per acre in the United States. 



Average yield of corr 





Jtrry Moorf yield of corn. 



How A BOY BEAT THE AVERAGE. 



Jerry Moore's acre yield of corn is here contrasted with the average yield of 

 the county. 



14. A yield of 14 bushels of wheat and 1,680 pounds 

 of wheat straw per acre entails what loss to the soil in 

 nitrogen? What loss in phosphoric acid? Potash? 



Solution for nitrogen: 

 14 bushels wheat weighs 14 X 60 pounds 840 pounds. 



According to our table, page 5, 2.4% O f this is nitrogen. 

 .024 X 840 pounds = 20 pounds. 



Our table shows that wheat straw is .6% nitrogen. 1,680 

 pounds would therefore contain 



.006 X 1,690 pounds = 10 pounds Nitrogen 



In an average crop of wheat there is removed from the 

 soil 20 pounds -f~ 10 pounds, or 30 pounds, of nitrogen an 

 acre. The amount of phosphoric acid and of potash may be 

 calculated in the same way, and will be found to be 9 pounds 

 and 13 pounds respectively. 



15. Determine number of pounds of each kind of 

 plant food the average crop of corn removes from the 

 soil when the yield is 29.4 bushels of corn and two tons 

 of stover per acre. 



