22 



The brands of ammoniated superphosphate and superphosphate with potash 

 showed the following deficiencies: — 



Superphosphate 

 with Potash. 



Brands deficient in one element . 

 Brands deficient in two elements 

 Brands deficient in nitrogen 

 Brands deficient in phosphoric acid 

 Brands deficient in potash . 



Four brands, nearly 10 per cent of the total number of ammoniated superphos- 

 phates, and two brands, 33 per cent of the total number of superphosphates with 

 potash, showed a commercial shortage of SI or over per ton. The extent of the short- 

 ages was as follows : — 



Amount of Shortage. 



Between $5 and $6 

 Between $3 and $4 

 Between $1 and $2 



Character of Plant Food. 



(a) Nitrogen. 



In those brands which carried a guarantee of 14 per cent or over of available plant 

 food (high-analysis brands), about 37 per cent of the total nitrogen was in mineral 

 form, and about 83 per cent of the total nitrogen was in active form. In those brands 

 which carried less than 14 per cent of available plant food (about 74 per cent of the 

 total number), about 37 per cent of the total nitrogen was in mineral form, and 77 

 per cent of the total nitrogen was in active form. The average total nitrogen in all 

 of the ammoniated superphosphates irrespective of grade had a percentage activity 

 of 80.32; the average total organic nitrogen had a percentage activity of 68.67; and 

 the average water insoluble organic nitrogen had a percentage activity of 56.02. 



(b) Phosphoric Acid. 



The average total phosphoric acid found in ammoniated superphosphates was 

 9.96 per cent; 75.5 per cent of this was in available form, and of the available phos- 

 phoric acid, about 60.38 per cent was in water soluble form. 



