20 



PRACTICE 9. 

 DETERMINATION OF NITROGEN IN FARM PRODUCE. 



Each group of students will work upon one of the following materials : 



1. Wheat 5. Oats. 



2. Corn. 6. Red Clover Hay. 



3. Corn Stover. 7. Alfalfa. 



4. Corn Cobs. 8. Oat Straw. 



Weigh out exactly 2 gm. of the material numbered with your group 

 number and determine the nitrogen in it according to the method given 

 in the Eighth Practice. 



Titrations cc. NH 3 



cc. NH 3 Percent N 



Average cc. NH 3 



Calculate the results obtained and with these record the results ob- 

 tained by three members of each group as indicated upon the following 

 page, valuing nitrogen at 15 cents per pound. How many tons of red clover 

 must be plowed under in order to supply in this way the nitrogen for a 

 loo-bushel crop of corn and a 75-bushel crop of oats in a corn, oats and 

 clover rotation ? 



Compute the pounds of nitrogen required to produce the crops given 

 in the table below. Compute the weight of sodium nitrate (95% pure), 

 which would supply the nitrogen found in these crops, and the cost of the 

 same. 



