26 



The average total nitrogen in the complete fertilizers had a percentage activity 

 of 83.40 per cent, the total organic nitrogen of 66.2 per cent, and the water 

 insoluble organic nitrogen of 56.9 per cent. 



Nitrogen in Ammoniated Superphosphates. — The quality of the 

 nitrogen used in these mixtures is shown by the following data: average 

 total nitrogen found, 3.50 per cent, nitrogen in form of nitrates and am- 

 moniates, 1.56 per cent, organic nitrogen, 1.94 per cent. It will be seen from 

 these figures that about 44.6 per cent of the total nitrogen was present in 

 mineral forms and 55.4 per cent in organic forms. About .71 per cent of the 

 organic nitrogen used was found soluble in water, and 1.23 per cent insoluble. 

 Of this latter, ,70 per cent was found active, and .53 per cent inactive by 

 laboratory methods. The percentage activity of the total nitrogen was 

 about 84.8 per cent, of the total organic nitrogen, 72.7 per cent, and of the 

 water insoluble organic nitrogen, 56.9 per cent. 



Brands of Mixed Fertilizer showing Inferior Forms of Nitrogen. — 

 One out of a total of 119 brands of complete fertilizers, and 5 out of a total 

 of 159 brands of ammoniated superphosphates, besides 1 brand of a peat 

 mixture and 9 brands of pulverized sheep manure, were found to contain 

 organic nitrogen, the water insoluble portion of which showed a low avail- 

 ability by the laboratory methods. Although this is a much better showing 

 than during the preceding year, yet it may be said that a very large number 

 of brands of mixed fertilizer hover around the danger mark. About 40 per 

 cent of the brands of both complete fertilizers and the ammoniated super- 

 phosphates shows an activity of the water insoluble organic nitrogen between 

 50 and 53 per cent by the alkaline permanganate method. 



The following table shows the brands of mixed commercial fertilizer show- 

 ing inferior forms of organic nitrogen. Some other brands showed the pres- 

 ence of inferior organic nitrogen but were passed without question, and are 

 not mentioned in the table on account of the minimum percentage of nitro- 

 gen guaranteed being more than made up by the active forms of nitrogen 

 present. 



