CONTROL SERIES NO. 158 



Mixtures Showing a Commercial Shortage of SI or More per Ton 



a See table of "Mixtures Substantially Complying with Guarantees." 



b Since this material is sold in small packages, a calculation of the shortage per ton is not 



feasible. Deficiency found is great enough for inclusion of this material with seriously 



deficient brands. 



EXPLANATION OF TABLE OF ANALYSES 



Guarantee. The plant food guarantee or the grade of each fertihzer 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 

 in that order. 



Mixtures Substantially Complying with the Guarantee. In addition to 

 those fertilizers that meet their guarantees in every respect, this table includes also 

 a list of those mixtures that have one or more elements below the guaranteed per- 

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



This table, in addition to the data mentioned in the next paragraph, contains 

 only results of analytical tests pertaining to the average amount of water insoluble 

 nitrogen present in each brand, since this information is of value to tobacco grow- 

 ers and other users of fertilizers containing a high percentage of this form of nitro- 

 gen. 



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

 those fertilizers that 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. 



