New York Agricultural Experiment Station. 665 



The cost of nitrogen and phosphoric acid averages less in fish-scrap 

 than any other materials examined, excepting tankage containing 

 meat and bone. One sample had been treated with acid and most of 

 its phosphoric acid rendered soluble. 



AMOUNT AND COST OF PLANT-FOOD IN BASIC SLAG PHOSPHATE. 



The 5 samples examined enable us to give the following figures: 



Table XIV. — Amount and Cost of Phosphoric Acid in Basic Slag 



Phosphate. 



The average cost of phosphoric acid in basic slag is somewhat more 

 than that of the available phosphoric acid in high-grade complete 

 fertilizers; it is the same as in mixtures of potash and acid phosphate; 

 it is more than in acid phosphate, bone and tankage. 



AMOUNT AND COST OF PLANT-FOOD IN GROUND ROCK PHOSPHATE. 



Under certain conditions, the use of untreated ground rock phos- 

 phate, often called "floats," is coming into use in increasing amounts. 

 The only quotation obtained is $13 a ton in the case of the 4 samples 

 examined. 



Table XV. — Amount and Cost of Phosphoric Acid in Ground Rock 



Phosphate. 



The selling price ($13) is too high for ordinary conditions in this 

 State. It is known that it can be obtained by farmers for $8.50 a ton. 

 At this price, one pound of insoluble phosphoric costs about 1.4 cents. 



