READY-MIXED FERTILIZER 



103 



of the fertilizer. Add the products ; the sum is the com- 

 mercial value of the fertilizer. 



EXAMPLE. What is the commercial value of one ton of complete 

 fertilizer which the printing on the bags guarantees to contain i .65 per 

 cent of nitrogen, 10 per cent of available phosphoric acid, and 2 per cejt 

 of potash ? 



Plant-food 

 in one ton 



Lbs. Cents 



Commercia 1 ' 

 value 



Nitrogen i .65 % x 2000 Ibs. = 



Available phos- 

 phoric acid 10% x 2000 Ibs. = 

 Potash 2% x 2000 Ibs. = 



33 Ibs. 33 x 15= $ 4.95 



200 Ibs. 

 40 Ibs. 



200 x 5 = 

 40 x 5 = 



IO.OO 



2.00 



$16.95 



The above calculation shows a commercial value of $16.95 when 

 nitrogen, phosphoric acid, and potash have the prices of 15, 5, and 5 

 cents a pound respectively. 1 



If the cash price asked by the dealer is many dollars per 

 ton above the estimated commercial value for. that year, 

 a calculation should be made to learn what it would cost 

 for the farmer to make his own fertilizer by mixing together 

 acid phosphate, cotton-seed meal, and kainit, or other 

 chemicals. 



EXAMPLE. What will it cost to make a home-mixed fertilizer, having 

 she same composition as the fertilizer given in the table, with cotton-seed 

 meal at $22 per ton, acid phosphate (with 16 per cent available phos- 

 phoric acid) at $15 per ton, and kainit at $14 per ton? The price 

 asked for the ready-mixed fertilizer is $21 per ton. How much meal, 

 phosphate, and kainit must be mixed in order to obtain an equivalent, 

 but less expensive, fertilizer? 



l These figures will answer for practice. To get the exact prices of nitro- 

 gen, phosphoric acid, and potash for any particular year, write to the State 

 Commissioner of Agriculture at the state capital. 



