198 SOILS AND FERTILIZERS 



The ton of fertilizer would then contain about 35 

 pounds of nitrogen, 189 pounds of phosphoric acid 

 and 53 pounds potash. These amounts are deter- 

 mined by multiplying the percentage composition by 

 the weight of material taken : 



Pounds. 



Nitrogen 225X0.155= 34.9 



Potash 425* X o. 125 = 53. i 



Phosphoric acid 135 X - 1 4 = 189.0 



The fertilizer would then contain approximately 1.75 

 per cent, nitrogen, 2.65 per cent, potash, and 9.45 per 

 cent, phosphoric acid. The percentage amounts are 

 obtained by dividing the total pounds by 20. This 

 fertilizer, if made at home from materials purchased 

 in the market, would cost, exclusive of transportation 

 and mixing, $18.79. 



Pounds. Cost. 



Nitrogen 34.9 @ 14^ cents = $5.06 



Phosphoric acid 189.0 @ 6 cents =11.34 



Potash 53.1 @ 4 l / 2 cents = 2.39 



Total $18.79 



A more concentrated fertilizer could be prepared by 

 using high-grade sulphate of potash, superphosphate, 

 and ammonium sulphate. A fertilizer composed of 

 these ingredients would contain : 



111 



Total % 6'S 



Pounds. Percent. pounds. Value. PL, 8 



300 Sulphate of ammonia 20 N 60 @ 14^ cents = $8.70 3.00 

 500 Sulphate of potash. . 50 K 2 O 250 @ 4^ cents =11.25 12.50 

 1200 Superphosphate 35 P 2 O 5 420 6 cents = 25.20 21.00 



Total $45.15 



