INSPECTION OF COMMERCIAL FERTILIZERS 11 



Mixing Efficiency Table. 



Fourteen different firms have registered five or more brands of mixed fertilizers. 

 On the basis of composition found by analysis as well as upon tonnage sold, the 

 above table shows to what extent each manufacturer was successful in avoiding 

 deficiencies in plant food guarantees in his mixtures. All of the fourteen firms pro- 

 vided a satisfactory average over-run in the three major plant food elements 

 guaranteed. 



Fertilizer Costs Compared. 



The approximate money value of several fertilizers may be compared by 

 dividing the average selling price of each grade by the average commercial valua- 

 tion as found or as guaranteed, assuming in the latter case that the plant food 

 guarantees are maintained. This will give the actual cost of one doUar of valuation. 

 (The valuations are obtained by multiplying the percentage or units of the several 

 forms of nitrogen, available phosphoric acid, and potash as given in the tables of 

 analysis by the unit value as published in the table of trade values; the sum of all 

 these items will be the commercial valuation of the fertilizer.) 



Acid and Basic Fertilizers. 



The following table shows the extent to which the mixed fertiUzers sold in the 

 state during the year contributed to soil acidity. 



These results Were secured by the use of the Pierre method modified to correct 

 for the equivalent basicity of the citrate insoluble phosphoric acid found in each 

 fertihzer (see page 101, Vol. XVII, No. 1, Journal of the Association of Official 

 Agricultural Chemists). 



Both basic and acidic results have been computed on the basis of the total 

 tonnage of the various brands sold in the gtate and are given in terms of tons of 

 carbonate of lime. The net acidity is obtained by deducting the total basicity 

 of the brands that were alkaline from the total acidity of the brands that were 

 acid, the results being expressed in terms of calcium carbonate. Data for each 

 manufacturer's brands are on file and will be furnished to the appropriate manu- 

 facturer upon apphcation. 



