HOMIC MIXTURKS I3I 



oartli nia\ be incorporated to insure a more even mixture. It 

 should be remembered that the chief advantage of buying factory 

 mixed fertiUzers is that they are better mixed and the farmer 

 cannot spend too much time in the process of thoroughly mixing 

 his fertilizer materials.* 



How to Calculate Percentages from Known Amounts. — Suppose 

 you want to find out the analysis of a mixture made up of the 

 following : 



Mixture. 

 600 lbs. acid phosphate analj'zing 14 % available phosphoric acid 

 150 lbs. sulphate of ammonia analyzing 20 ''/c nitrogen 

 100 lbs. sulphate of potash analyzing 50 % potash. 



850 lbs. Total. 



To find out the number of pounds of available phosphoric acid, 

 nitrogen and potash in the above mixture, make the following 

 multiplication. 



6 X 14 = 84 lbs. available phosphoric acid 

 1.5 X 20 = 30 lbs. nitrogen 

 I X 50 = 50 lbs. potash, 



To calculate the percentages of available phosphoric acid, 

 nitrogen and potash, divide the amounts of the constituents by 

 the total amount of the mixture. 



Available phosphoric acid, lbs. 84 -f- 850 ^ 9.88 % available phosphoric acid 



Nitrogen lbs. 30 -i- 850 = 3.53 Jo nitrogen 



Potash lbs. 50 -i- 850 = 5.88 fo potash. 



If percentages are wished when one of the materials contains 

 two constituents, the calculations may be made as follows : 

 Mixture. 



200 lbs. dissolved bone analyzing \ '^ J available phosphoric acid 



-' ° ( 2.5 ^ nitrogen 

 100 lbs. nitrate of soda analyzing 18.84 % ammonia 



50 lbs. carbonate of potash analyzing 64.00 % potash. 



350 lbs. Total. 



The dissolved bone superphosphate furnishes two constituents, 

 available phosphoric acid and nitrogen, so we must take these 

 into consideration in our calculations. 



