341 



Value of Fertilizing Constituents op Weeds of Indiana. 

 Analysis of Ironweeds. 



By Fkank INIatiifrs and Miss Gail M. Stapp. 



This paiiei" is the bL'.i,'iiiniii.::; of work to determine tlie value of weeds. 

 Ironweeds, wliich grow everywhere in great abundance, were selected for 

 analysis. .Samples were collected from the university campus on Sep- 

 tember 29, 1911. They were cut into small pieces and dried for several 

 days in the air. Finally the material was dried for several hours at about 

 90°. The analysis was made upon this dried sample, but the results were 

 calculated to the air dried material. The loss on drying was 14 per cent. 

 The analyses' of several other substances are given in this table for com- 

 l)arison. 



Ironweed.-i 



Blue gra,s.s . . . 

 Oxeye daisy 

 Wheat straw 



Foxtail 



Corn stover* 

 Timothy hay 

 Red top ... 

 Red clover 



*The values used for N, P2O5 and KjO are 18, 6 and 6 cents per pound respectively. 



These calculations do not consider the value of the organic matter, 

 which is really the thing of greatest importance in manures and soiling 

 crops. The values assigned represent the cost of a commercial fertilizer 

 containing the same amounts of nitrogen, phosphoric acid and potash. 



'Yearbook of the U. S. Dept. of Agriculture, 20: 611 (1896). 



