30 



In judging the quality of the organic nitrogen 

 Interpreting in a fertiHzer one should be guided by the 



the Quality percentage activity of the total organic nitro- 



of the gen as well as the percentage activity of the 



Nitrogen. water insoluble organic nitrogen and a fer- 



tilizer should not be condemned until due con- 

 sideration is given for any excess of nitrogen furnished over the 

 minimum guarantee. For instance, out of a total of 41 brands 

 in this year's inspection which showed an activity of the water 

 insoluble organic nitrogen of less than 50%, 16 of them undoubt- 

 edly owed this low availability of the organic nitrogen to the pres- 

 ence of a small amount (200 lbs. more or less) of dry ground peat 

 which had been used as a conditioner. The minimum nitrogen 

 guarantee in these goods was evidently made up of nitrogen in 

 an available form. It speaks well for the laboratory method that 

 one is able to detect the presence of so small an amount of low 

 grade nitrogen; since the 200 lbs. of peat would not furnish over 

 5 lbs. or about .25% of nitrogen. 



Although no hard and fast rule can be laid down, yet fertili- 

 zers which contain a considerable quantity of organic nitrogen, 

 only small amounts of which are water soluble and in which less 

 than 50% of the water insoluble organic nitrogen is in active form, 

 should be classed as low grade. (Cases should be viewed with 

 suspicion where less than 50% of the water insoluble organic ni- 

 trogen is found active, even though the fertilizer may show con- 

 siderable organic nitrogen in water soluble form.) It should be 

 borne in mind that the laboratory method, although probably 

 showing a higher activity of the nitrogen in fertilizers than is 

 shown by vegetation experiments, does not pretend to give the 

 true availability as shown by field or pot tests. It will and does 

 distinguish, however, between the good and inferior forms of 

 organic nitrogen used in commercial fertilizer mixtures. 



On the basis of the above statements, there seems good reason 

 to conclude that at least a portion of the organic nitrogen found 

 in the following brands was derived from inferior sources : 



Alphano Humus Co., New York City. Bowker Fertilizer Co., Boston, Mass. 

 Prepared Humus. Pulverized Sheep Manure, 



Ammoniated Food for Flowers. 

 Armour Fertilizer Works, Baltimore, , „ , „ „ -r, . 



j^^ Jos. Breck & Sons, Boston, Mass. 



Complete Potato. Sheep Manure. 



Buffalo Fertilizer Co., Buffalo, N. Y. 



Fish Guano. 



Beach Soap Co., Lawrence, Mass. 



Market Garden Fertihzer, 



Advance Fertilizer Hubbard Fertilizer Co., Baltimore, Md. 



Reliance Fertilizer, Blood, Bone and Potash, 



Lawn Dressing. Farmers' I. X. L. 



