FERTILIZERS 37 



grower for, say, $35 per ton and No. 1 would be the 

 best buy for the grower, and No. 2 the best sale for 

 the agent or manufacturer. 



It is quite possible for the nitrogen to be in cheap 

 form also and worth considerably less than 20c. per 

 pound. The nitrogen from raw bone is worth less 

 than that from blood, or guano, or tankage. 



So the value of a ton of fertilizer is based upon 

 the source or form of the nitrogen, phosphoric acid 

 and potash, and the quantity of each. 



COST OF NITROGEN. 



56. Nitrate of soda, 96% pure, 16% nitrogen at 

 $50 per ton. This yields 307 pounds of nitrogen, 

 which at $50 per ton, equals 16. 3c per pound or 

 $3.24 per unit of 20 pounds. 



Dried, ground blood, analyzing 14% nitrogen, or 

 280 pounds at $60 per ton, equals 21c. per pound, 

 or $4.20 per unit. Market values change constantly. 

 At times, nitrate may be worth $60 and blood 

 worth $55 per ton. 



COST OF PHOSPHORIC ACID. 



57. Steamed, ground bone (not acidulated) at 

 $35 per ton, containing 25% phosphoric acid (500 

 pounds (equals 7c. per pound, less the value of 1% 

 nitrogen (20 pounds) contained in steamed bone at 

 20c. per pound would make the net cost of phos- 

 phoric acid about $1.24 per 20 pounds, or 6%c. per 

 pound. Thomas Phosphate Powder, 17% phos- 

 phoric acid, at $22.50 per ton, would cost $1.30 per 

 unit, or 6M$c. per pound. 



COST OF POTASH. 



58. The sulphate yielding 49% actual potash can 

 be bought for $60 per ton, making the actual potash 

 cost 6c. per pound or $1.20 per unit, (20 pounds). 



