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10 



Food for plant food can be bought for in our markets, in just as 

 Plants good, if not better, forms. 



The New Jersey Experiment Station analyzed 195 

 different samples of brands of "Complete Fertilizers," and 

 published the results in Bulletin No. 89, October loth, 

 I 892. It was found that, in some instances, complete ferti- 

 lizers that sold for I34.00 to $36.00 per ton only contained 

 plant food worth 1 15.00 to 1 17.00 ! But they were not all 

 as bad as this. The average of all brands analyzed was as 

 follows : They contained 2.74 per cent Nitrogen, 7.70 per 

 cent available phosphoric acid, and 4.50 per cent potash. 

 The selling price was $34.23 per ton and the actual agricul- 

 tural value 1 2 5.66 per ton. By this is meant that the same 

 amount of actual plant food that is contained in the "com- 

 plete fertilizers," costing I34.23, could be purchased in the 

 open market, in just as good forms, for $25.66. As a 

 matter of fact, it could be purchased for much less than 

 this in quantities often tons or more. In one ton of the 

 above " average fertilizer," selling for I34.23, there is 

 154 pounds available phosphoric acid, which can be bought 

 for 554^ cents per pound in superphosphate or "acid phos- 

 phate," as it is called by the trade. This 154 pounds of 

 phosphoric acid is therefore worth $8.09. There is 54V5 

 pounds Nitrogen; which can be bought in Nitrate of Soda 

 for 15 cents per pound, making it worth I8.22 ; 90 pounds 

 potash, worth 4.^4 cents per pound, equals I4.05, making in 

 all $20.36 for the plant food contained in a ton costing I34.23. 

 But this does not tell the whole story. The Nitrogen 

 contained in these " complete fertilizers " is often in a form 

 that is not available to the plants until it has undergone 

 oxidation in the soil and become converted into Nitrate. 

 The time required to do this varies from a few days to 

 years, according to the temperature of the soil and the kind 

 and condition of the material used. In calculating the 

 value of complete fertilizers, Nitrogen in the form of 

 sulphate of ammonia, which has to be converted into 

 Nitrate before it is available, is reckoned at two cents per 

 pound higher than it can be bought in the form of Nitrate 

 of Soda, This is not because the Nitrogen in sulphate of 

 ammonia is any better than in Nitrate of Soda, but because 

 it costs more. This makes the fertilizers appear to be worth 

 more than they really are. But taking the figures as they 



