INSPECTION OF COMMERCIAL FERTILIZERS 



59 



The tables show tlie yield of dry matter and the iihosjjhoric acid recovered 

 in the above-ground parts of the plant and the iihosjjhoric acid availability 

 of each plant on the basis of both dry matter yield and phosjihoric acid re- 

 covery. In calculating the average relative availability of the phosphoric acid, 

 the increase in yield due to the use of superphos]ihate as compared to the yield 

 of the no-phosphate pots is placed at 100, and is used as the standard of com- 

 parison. 



Series H. Optimum Phosphoric Acid. 



'Nitrogen and potash increased one-half 



