IS 



Fertilizer Brands Showing Inferior Insoluble Organic Nitrogen. — Con. 



' One analysis, one sample. One other analysis, two samples, showed an activity of 50% by the alkaline 

 permanganate method. 



' One analysis, one sample. One other sample showed an activity of 56.4% by the alkaline permanganate 

 method. 



' One analysis, three samples. One other analysis, three samples, showing a low activity was passed, 

 the minimum guarantee having been met by the more active forms of nitrogen. 



Although a relatively large number of brands showed the presence of inferior 

 forms of organic nitrogen, yet most of these were from fifms entering the Massachu- 

 setts markets for the first time and apparently unused to the close scrutiny which 

 is given this feature of the fertilizer control work in this state. Although naturally 

 disappointed at the poor showing of their fertilizers in this respect, they expressed 

 themselves as pleased with the effort to improve the quality of the organic nitrogen 

 used in fertilizer mixtures, and gave the assurance that the quality of the organic 

 nitrogen used in the mixtures sold by them in Massachusetts another season would 

 be satisfactory in every way. 



It may be said of the Piedmont-Mt. Airy Guano Co., the United States Guano 

 Co., and the Maine Farmers Exchange, that they claimed to have provided a suffi- 

 cient nitrogen overrun in their mixtures so that the minimum nitrogen guarantee 

 would be fully met by the more active forms of nitrogen. Although there is evi- 

 dence that this was done m many instances, yet apparently sufficient care was not 

 taken to make this practice uniform. The use of a low grade organic ammoniate 

 as a conditioner is perfectly legitimate, provided enough nitrogen to meet the 

 minimum guarantee is supplied in the more active forms. 



With the exceptions noted, the quality of the organic nitrogen found in the mixed 

 fertilizers sold in Massachusetts for the season has been satisfactory. 



There is evidence with each successive year that most fertilizer manufacturers 

 endeavor to select organic ammoniates for their mixtures which show a satisfactory 

 nitrogen activity, and with new products continually coming to the front, this 

 practice camiot be over-emphasized. Yet in view of the fact that nitrogen activity 

 by laboratory methods does not attempt to measure nitrogen availability, which 

 can be determined only by plant growth, it is always desirable to check laboratory 

 results by vegetation tests, particularly with new products and with materials of 

 unknown availability. During the past season such an experiment has been con- 

 ducted on an imported product known as Rehmsdorf Tankage, and on Pulverized 

 Poultry Manure, which by laboratory methods has not shown a satisfactory activity 

 of the water insoluble nitrogen. 



The results of this experiment are given on pages 13-15. 



