New York Agricultural Experiment Station. 133 



cost of a fertilizer is made up of several different elements, a 

 commercial valuation includes only the first of the elements enter- 

 ing into the total cost, that is, the retail cash cost in the market of 

 unmixed raw materials. 



Valuation and Agricultural Value. — The agriGultiiral value of 

 a fertilizer depends upon its crop-producing 2>ower. A commercial 

 valuation does not necessarilj have any relation to crop-producing 

 value. For a particular soil and crop, a fertilizer of comparatively 

 low commercial valuation may have a higher agricultural value ; 

 while for another crop on the same soil or the same crop on another 

 soil the reverse might be true. 



Simple Rule for Calculating Approximate Coimmercial Valua- 

 tion OF Fertilizers. 



Multiply the per cent, of nitrogen by 3 and add to the product 

 the figures representing the per cent, of available phosphoric acid 

 and of potash. The sum expresses in dollars and cents tbe approxi- 

 mate commercial valuation of the fertilizer. 



Example. — A fertilizer coutaius 



Nitrogen 4 . 13 per cent. 



Available phosphoric acid 8.52 per cent. 



Potash 10.54 per cent. 



4.13 (percent, of nitrogen) multiplied by three, equals $12.39 



8.52 (per cent, of available phosphoric acid) 8.52 



10.54 (per cent, of potash) 10.54 



Total, per ton •. $31 . 45 



If a fertilizer contains only one or two of the three essential fer- 

 tilizing ingredients, the rule can be applied in a modified form. In 

 case of fine bone-meal, use the total phosphoric acid in place of the 

 available in making the calculation. 



While this rule is not exact, it gives results that are fairly accu- 

 rate and has the great advantage of simplicity. It does not take 

 the insoluble phosphoric acid into consideration at all. 



For the benefit of those who desire a more exact method of cal- 

 culating the commercial valuation of fertilizers, we give below a 

 more detailed rule. But previously we give methods for calculating 

 from one compound to another, and also methods for making valua- 

 tions of unmixed fertilizing materials. 



