MIXING OF FERTILIZERS 



169 



Tabulating, we have the following: 



(3) Given, material too low in composition to make a 

 formula of high percentage composition; overcome the difficulty. 



PROBLEM : To apply 1000 pounds of a fertilizer per acre 

 for truck, analyzing nitrogen equivalent to 5 per cent 

 ammonia, 8 per cent phosphoric anhydride, and 8 per cent 

 potash. Source of phosphoric acid, 14 per cent acid phos- 

 phate; source of nitrogen, ground fish scrap containing nitro- 

 gen equivalent to 10 per cent ammonia and 6 per cent avail- 

 able phosphoric acid; source of potash, sulphate of potash 

 containing 48 per cent water-soluble potassium oxide (K20). 



Apply the same process outlined in (2), whereby it is 

 found that 1000 pounds of dried ground fish, 714 pounds 

 of 14 per cent acid, and 333 pounds of sulphate of potash 

 contain the plant food desired for compounding 1 ton of 

 fertilizer analyzing nitrogen equivalent to 5 per cent of 

 ammonia, 8 per cent phosphoric anhydride, and 8 per cent 

 water-soluble potash; but that the mixture weighs 2047 

 pounds instead of 2000 pounds. Therefore the plant food 

 is mixed in the same proportions as a " 5-8-8 " fertilizer 

 (fertilizer containing 5 per cent ammonia, 8 per cent phos- 



