INSPECTION OF COMMERCIAL FERTILIZERS 9 



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 and Brand," 

 and is expressed as nitrogen, available phosphoric acid, and water soluble potash 

 and in that order. 



Commercial Shortages. Lender the heading "Approximate commercial short- 

 age per ton" is shown the commercial valuation of the deficiencies or tests found 

 below the guarantee. No allowance is made for the value of overruns in other ele- 

 ments which are above guarantee. The manufacturer makes a definite guarantee 

 regarding the minimum percentage of each element which each grade shall con- 

 tain. If a farmer buys a 5-8-7 fertilizer he has every right to expect and insist 

 that he shall receive a 5-8-7 grade and not a 4—8-10 grade, even though the latter 

 may have an equal or higher commercial value. Figuratively speaking, plants 

 think in terms of pounds of nitrogen, available phosphoric acid, potash, and other 

 plant food elements, and not in terms of dollars and cents. As far as plant growth 

 is concerned, an overrun of 30 or 40 pounds of potash in a ton of fertilizer does 

 not compensate for a shortage of 15 or 20 pounds of nitrogen. 



Deficiencies are emphasized by boldface type. 



Mixtures Substantially Complying with the Guarantee. In addition to 

 the analysis of those fertilizers which meet their guarantees in every respect, this 

 table includes also those mixtures which have one or more elements below the 

 guaranteed percentage but have a shortage of less than $1 per ton. 



Inferior Nitrogen. The presence of inferior forms of organic nitrogen is indi- 

 cated by footnotes. 



Potash Forms. Tests for chlorine are made only on tobacco mixtures and on 

 those fertilizers which carry a guarantee of potash in forms other than muriate. 

 When the amount of chlorine present in any brand exceeds the tolerance allowed 

 for that brand, this fact is indicated by a footnote. 



