70 FUNDAMENTALS OF AGRICULTURE. 



this example we will select muriate of potash. The 

 above table gives the composition of acid phosphate 

 as 14 per cent, available phosphoric acid, the nitrate 

 of soda as 15.5 per cent, nitrogen and the muriate of 

 potash as 50 per cent, potash. Since 8 per cent, avail- 

 able phosphoric acid (the amount desired in the finished 

 product) is equal to 8 Ibs. of available phosphoric 

 acid to every 100 Ibs. of fertilizer, in 2,000 Ibs. there 

 will be needed 8x20 or 160 Ibs. of available phos- 

 phoric acid. In the same way we find that we must 

 have 33 Ibs. of nitrogen and 40 Ibs. of potash. The 

 following statement represents this more clearly: 



Amount wanted Amount required 

 per hundred. per ton. 



Available phosphoric acid 8 Ibs. x 20 = 160 Ibs. 



Nitrogen i . 65 Ibs. x 20 = 33 Ibs. 



Potash 2 Ibs. x 20 = 40 Ibs. 



The next step is to find out the number of pounds 

 of acid phosphate required to furnish 160 Ibs. of avail- 

 able phosphoric acid. The table of composition states 

 that 100 Ibs. of acid phosphate contains 14 Ibs. of 

 available phosphoric acid. Then 14 : 100 as 160 : x 

 (number of pounds of acid phosphate required). 

 Or I4x = 16,000 x = 1,143 Ibs. The pounds of 

 nitrate of soda and muriate of potash are figured in a 

 similar way. 



14 : loo = 1 60 : number of pounds of acid phosphate required. 

 15.5 : 100 33 : number of pounds of nitrate of soda required. 

 50 : 100 = 40 : number of pounds of muriate of potash required. 



In other words, the quantities of fertilizers as stated 

 below will be needed to make one ton of fertilizer of 

 the desired composition. 



1143 Ibs. of acid phosphate containing 14% available phosphoric acid. 

 213 Ibs. of nitrate of soda containing 15.5% nitrogen. 

 80 Ibs. of muriate of potash containing 50% potash. 



1436 Ibs. Total. 



