12 



CONTROL SERIES No. 81 



Summary of Data on Acid and Basic Fertilizers. 



With an increase over 1934 of 2,954 tons of mixed fertilizer inspected, the net 

 acidity, expressed in tons of carbonate of lime, is 1,268 tons less than for 1934. 

 This shows a more liberal use of fine ground hmestone as a conditioner in mixed 

 fertilizers. 



Explanation of Tables of Analyses. 



Guarantee. The plant food guarantee or the grade of each fertilizer is made 

 a part of the trade name under the heading "Name of Manufacturer, Brand and 

 Grade," and is expressed as nitrogen, available phosphoric acid and water soluble 

 potash and in that order. 



Commercial Shortages. In the table designated "Mixtures showing a com- 

 mercial shortage of $1 or more per ton," the column headed "Approximate com- 

 mercial valuation per ton" gives the sum of the valuation of each plant food 

 element computed from the analysis by use of the trade values adopted by the 

 Massachusetts Fertilizer Control for 1935, which appear on a preceding page of 

 the bulletin. 



Under the heading "Approximate commercial shortage per ton" is shown the 

 commercial valuation of the deficiencies or tests found below the guarantee after 

 allowance is made for the value of overruns or tests above the guarantee. 



Deficiencies are emphasized by boldface type. 



Mixtures Substantially Complying with the Guarantee. In addition to 

 the analysis of those fertilizers substantially complying with the guarantee, this 

 table includes also those mixtures that are more or less out of balance; that is, 

 having deficiencies in one or more plant food elements, but having overruns 

 which largely offset the value of the deficiencies. 



"Number of samples" indicates the number of samples included in the com- 

 posite which was analyzed. 



Inferior Nitrogen. The presence of inferior forms of organic nitrogen is indicated 

 by footnotes. 



Potash Forms. Wherever tests for chlorine showed a sufficient amount present 

 to unite with all of the potash foimd, the source of the potash is designated as 

 muriate. Wherever insufficient chlorine was found to account for all of the 

 potash it is evident that forms of potash other than muriate were used. In such 

 cases, the figures under the sub-heading "As muriate" do not imply necessarily 

 that muriate of potash was actually added to the mixture, but that chlorine was 

 present, probably from impurities in the fertilizer chemicals, in amounts to 

 account for the percentage of potash indicated. The balance of the potash found 

 is listed under the sub-heading "In forms other than muriate" and may be derived 

 from sulfate, nitrate, or carbonate, as the case may be. 



