27 



teed 1.80%; available phosphoric acid found .89%, guaranteed 

 1%; potash found .95%, guaranteed 1%. 



Quality of Plant Food. 



There is a considerable variety of opinion 

 Character of among fertilizer manufacturers as to what 



Nitrogen proportion of the nitrogen in a given fertilizer 



Used. formula should be present as nitrates and 



ammoniates (mineral forms) and as organic. 

 Most of the formulas tested in this year's inspection have a por- 

 tion of both forms present. In the low grade fertilizers 60%, 

 and in the high and medium grades 47% of the nitrogen was 

 present in organic forms. Another significant fact is that out of 

 17 analyses which showed a low activity of the water insoluble 

 organic nitrogen (and to which special attention is called on a 

 subsequent page ) 9 or 53% were fertilizers which valued commer- 

 cially less than $15 per ton; in other words, were low grade goods. 

 Three out of the 17 were from medium grade goods and 5 or about 

 29% were from high grade fertilizers. The above data would 

 indicate a tendency to use a lower grade of material in supplying 

 the nitrogen in the cheaper grades of fertilizer and is another 

 strong argument in favor of the purchase of high grade formulas. 

 It seems of interest to publish here a summary table showing 

 the average amount, form and quality of nitrogen used by each 

 manufacturer in the brands sold for 1912. See next page. 



