PLANT FEEDING. 25 



Analyses on tags and sacks. In purchasing a ferti- 

 lizer it is always necessary to interpret correctly state- 

 ments and calculations, otherwise the purchaser may be 

 deceived as to its real plant food value. Remember that 

 available phosphoric acid, nitrogen, and potassium are 

 wanted, not high-sounding names or elaborate analyses. 



Take the following analysis : 



Fertiliser Analysis. 



Per cent 



Ammonia, 3 to 4 



Phosphoric acid (soluble), 10 to 12 



Phosphoric acid (insoluble), 1 to 2 



Total phosphoric acid, 11 to 14 



Potash (actual), 1.63 to 2.16 



Sulphate of potash, 3 to 4 



This reduced to its true meaning reads as follows : 



Nitrogen, 2.47 



Phosphoric acid, 10.0 



Potash, 1.62 



79. A special potato fertilizer sells for $35 per ton. 

 It analyzes as follows: 



Per cent 



Moisture, 10 to 15 



Ammonia, 2 to 2.25 



Available phosphoric acid, 8 to 9 



Equivalent to bone phosphate of lime, 20.74 to 24.01 



Insoluble phosphoric acid, 2.25 to 2 



Potash, 8 to 8.50 



Equivalent to sulphate, 11.80 to 13.72 



What is the true meaning and what is the plant food 

 value in a ton? 



Important truth. In buying fertilizers reduce all fer- 

 tilizers to terms of nitrogen, available or soluble phos- 

 phoric acid and potash. Pay no attention to others, for 

 they are of no value and are deceptive. Use only the 

 lowest percentage for each element, as it more nearly 

 represents the truth. 



