INSPECTION OF COMMERCIAL FERTILIZERS 13 



Summary of Low Tests in Mixed Fertilizers. 



Brands deficient in one element 



Brands deficient in two elements 



Brands deficient in tiiree elements 



Brands deficient in nitrogen 



Brands deficient in available phosphoric acid 



Brands deficient in potash 



117 

 38 

 6 

 58 

 59 

 94 



91 



10 



2 



29 

 34 

 54 



69 

 26 



54 



Serious Commercial Shortages in Mixed Fertilizers. 



The above tables show that of the 326 brands analyzed, 215, about 66 per 

 cent, were found to have no deficiencies. Of the 976 guarantees made, 152, 

 or 15.6 per cent, failed in passing, as compared with 11.4 per cent in 1927 and 

 22 per cent for 1926. 



Of the total number of brands analyzed, about 21 per cent failed to meet 

 their guarantee in nitrogen, 8 per cent in available phosphoric acid and 16.6 

 per cent in potash. This is about two and one-half times more nitrogen defi- 

 ciencies, about the same potash, and 8 less available phosphoric acid shortages 

 than were recorded for 1927. 



Nine more brands showed serious commercial shortages than for the previous 

 year. 



Mixing Efficiency. 



Assuming that the analytical results, tonnage sold, as well as sampled, and 

 minimum plant food guarantees are a fair index of the composition and claims 

 for each grade counted, the following table gives the average margin of overruns 

 or deficiencies actually furnished by each manufacturer having four or more 

 brands registered and sampled. 



