22 



BRANDS OF MIXED FERTILIZER SHOWING INFERIOR FORMS 



OF NITROGEN. 



Out of a total of 338 brands of mixed fertilizer, only 2 were found to con- 

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

 ability by the laboratory method. These were Mapes Potato Manure, which 

 showed an activity of the water insoluble organic nitrogen of 37.40 per cent 

 by the alkaline permanganate method and 69.80 per cent by the neutral 

 permanganate method, and the Virginia-Carolina Chemical Company's Owl 

 Brand, which showed an activity of the water insoluble organic nitrogen of 

 38.60 and 75.20 per cent, respectively. Besides these, 2 brands of peat mix- 

 tures and 8 of pulverized sheep manure were noted. From their general 

 make-up these latter products are expected to contain organic nitrogen of 

 inferior quality. As in previous years, a large number of both complete ferti- 

 lizers and ammoniated superphosphates ran but slightly above the passing 

 mark, and it is an open question if the standard of 50 for the alkaline per- 

 manganate method and 85 for the neutral permanganate method should not 

 be raised to 55 and 90. 



A STUDY OF THE GRADES OF MIXED FERTILIZERS SOLD IN 



MASSACHUSETTS. 



Several years ago the National Fertilizer Association went on record as 

 advocating the manufacture and sale of fertilizer mixtures which would carry 

 a minimum of 14 per cent of available plant food. This action was expected 

 to result in the withdrawal from the trade of those brands so low in analysis 

 as to make their manufacture, transportation and sale of doubtful economy. 

 This station has for many years tried to discourage the purchase of low-analj'- 

 sis fertilizer mixtures in general by pointing out the increased cost of the 

 plant food which they contain as well as the uneconomic practice of their 

 transportation and handling. The following studies have been made to ascer- 

 tain if these agencies have been effective in decreasing the purchase of those 

 brands which carry less than 14 per cent of available plant food, and which 

 for convenience we will designate as loAV-analysis fertilizers. The following 

 table shows the conditions for five years prior to the World War, as com- 

 pared with the season of 1920. This table includes only those brands which 

 furnish the three elements, — nitrogen, phosphoric acid and potash, — for 

 the reason that prior to 1915 practically all of the mixed goods carried water 

 soluble potash, while during the war and at the present time many brands 

 carry only nitrogen and phosphoric acid and are classed as ammoniated super- 

 phosphates. 



