SOURCES OF PLANT FOOD 



in steamed bone meal, for $30.00 in acid phosphate, and for $65.00 

 in " complete " fertilizer. 



TABLE 24. FERTILITY IN MANURE, ROUGH FEEDS, AND FERTILIZERS 



1 About two tons of fresh farm manure are required to produce one ton of com- 

 mon barnyard manure six months old, with losses about as indicated. 



2 Wood ashes also contain about 1000 pounds of lime (calcium carbonate) per 

 ton. 



3 This is the average composition and the average selling price of twelve brands 

 of so-called "complete" fertilizer offered for sale in Illinois. Only 70 pounds of 

 the phosphorus is guaranteed available, 18 pounds being insoluble. The cost of 

 88 pounds of phosphorus in raw rock phosphate would be $2.64. 



