394 



STxVTE BOARD OF AGRICULTURE. 



is made by adding an aminoniatc !<• a leady-made acid phosphate by the 

 dry-mix process then it would be necessary to use a 16% phosphate in 

 most, cases and the extra cost of the mixture over and above the same 

 amouut of 1(5% acid phospliate should be charged to the ammonia. Fur- 

 thermore, it is not oiir purpose to attempt to show actual values but to 

 demonstrate the difference in cost of the plant-food to the farmer between 

 the low and high grade fertilizers. In the case of the animoniated phos- 

 phates sold in the Htate during the year the dillerence between the. cost 

 of the ammonia in the 1/0-12-0 and the 2-12-0 formulas is very marked and 

 a glance at the above table should deter any thoughtfnl person from pur- 

 chasing the lower grade fertilizers. We are not in any way criticising the 

 manufacturers' prices on the lower grade formulas since, for aught we 

 know, the retail prices that prevailed last year on these formulas may be 

 as low as it would be possible to make them and provide a fair profit to the 

 manufacturers. However, we do know that those farmers who purchased 

 the low^er grade formulas paid a much higher cost per unit of plant-food 

 than did those who bought the higher grade goods. 



In arriving at the unit cost of the potash we have followed the same 

 method as used in determining the unit cost of ammonia except that we 

 used the phosphate-potash mixtures. There was a much smaller amount 

 of these mixtures sold in Michigan during 1918 than of the animoniated 

 phosphates but the number of samples obtained were probably just as 

 large in proportion to the amount sold so that the average retail prices 

 should be as reijresentative as in the case of the animoniated phosphates. 



Here, also, we find that in the higher grade or higher analysis mixtures 

 the cost per unit of potash is considerably lower than in the lower grade 

 goods. 



Now, if we use the lowest unit values for ammonia, phosphoric acid and 

 potash that have been obtained in the various cases (ammonia |0.!»(», phos- 

 phoric acid |1.GG, potash .|8.04) and compute the value of the various 

 complete fertilizers we obtain some very interesting data. 



Formula. 



1 - 8 -5 . . . 



2 -12 -2 



2^i- 8 -2 



2-8-2 



2 - 8 -1 



1 - 8 -2 



1 -12 -1 



1 -10 -1.2 



1 - 9 -1 



1 - 8 -1 



M - 8 -1 



J^ -10 -1 



1 - 7 -1 



H-llM -Vt. 



*Fal\ prices only. 



