November, 1924] fertilizer inspection, 1924 7 



plete fertilizers contain both forms of nitrogen, we can 

 approximate an average and use the values of $0,264 per 

 pound and $5.28 per unit for nitrogen of complete fertili- 

 zers. These figures w^ill not give the price at which fertili- 

 zers should be sold within the state, but they can be used 

 to determine the relative value of the different brands 

 which may be offered to the purchaser. 



PRICES OF PLANT FOOD MATERIALS. 



Per Unit Per lb. 



Nitrogen $5.28 $0,264 



Phosphoric acid ( P2 O5 ) available. ... 1.64 0.082 



Potash (K2 O) water soluble 0.86 0.043 



Either the unit or the pound method can be used to 

 calculate the commercial value of the fertilizer. If we have 

 a fertilizer with the following guaranteed analysis: 



Nitrogen total 3.00% 



Phosphoric acid (P2 O5) available 8.00% 



Potash (K2 O) water soluble 2.00% 



By the unit method we find : 



Nitrogen 3 x $5.28=$15.84 



Phosphoric acid available 8 x $1.64= 13.12 



Potash (K2 O) water soluble 2 x $0.86= 1.72 



Total commercial value $30.68 



By this method we multiply the per cent of each 

 plant food by the cost per unit and then add these figures 

 to give the total value. 



Employing the pound method we obtain: 

 3 X 20=Number of pounds of nitro- 

 gen in a ton .\ . . 60 X 0.264=$1 5.840 



8x20=Number of pounds of phos- 

 phoric acid in a ton.... 160x0.082= 13.120 

 2 x 20=Number of pounds of potash 



water soluble in a ton.. 40x0.043= 1.720 



Total commercial value $30,680 



