5 N. H. AGR. EXPERIMENT STATION [Bulletin 201 



soluble potash sold for an average price of $126.50 per ton. 

 One ton contained 0.515X2000 lbs. or 1030 lbs. of water 

 soluble potash. The cost per lb. was $126.50-=- 1030 or 

 $0,122 per lb. and one unit of water soluble potash cost 

 2oX$o.i22 or $2.45. 



The average cost of nitrate of soda containing 15 per 

 cent nitrogen is $80.00 per ton. One ton contains 2000X0.15 

 or 300 lbs. nitrogen which makes the cost $80.00-1-300 or 

 approximately $0.27 per pound and the price per unit is 

 20X$o.27 or $5.40. The average cost of tankage is $55.00 

 per ton and it contains an average of 5.58 per cent nitrogen 

 and 5.50 per cent available phosphoric acid. The value of 

 the 5.5 units of phosphoric acid is 5.5X$i-75 or $9.62 mak- 

 ing the nitrogen cost $55.00 — $9.62 or $45.38. The cost per 

 unit of nitrogen then is $45.38-^-5.58 or $8.13 and the cost 

 per lb. is $0,405. If we assume that our complete fertilizers 

 contain both forms of nitrogen we can approximate an 

 average and use $0.32 per lb. and $6.40 per unit. 



These figures will not give the price at which fertilizers 

 should be sold within the state but they can be used to 

 determine the relative value of the same brands which may 

 be offered to the purchaser. 



PRICES OF PLANT FOOD MATERIALS. 



Nitrogen 



Phosphoric acid (P2O5) available 



Potash (KoO) water soluble 



Either the unit or the pound method can be used to cal- 

 culate the commercial value of the fertilizer. If we have a 

 fertilizer with the following guaranteed analysis: 



Nitrogen total 3-00% 



Phosphoric acid (PaO'g) available 18.00% 



Potash (K._iO) water soluble 2.00% 

 by the unit method we find : 



Nitrogen 3 X $6.40 = $19.20 



Phosphoric acid available 8 X  1.75 = 14.00 



Potash water soluble 2 X 2.45 = 4.90 



Total commercial value $38.10 



