No. 6. DEPARTMENT OP AGRICULTURE. 52l 



fertilizer contains no readily available nitrogen, but merely that part 

 or all of the insoluble nitrogen is derived from low-grade sources, 

 barring cases in which cyauamid is one of the fertilizer ingredients. 

 These low grade materials may be such as are listed in Section 4 of 

 the law, or others in common use, such as garbage tankage, peat or 

 mora meal; and they may, if of animal origin, have had their nitro- 

 genous material changed almost entirely to an available condition 

 by Svet mixing,' which has, however, little improving effect upon the 

 nitrogenous constituents of garbage tankage and mora meal, and 

 little more upon those of peat. 



The use of such low-grade materials is either to make the fertilizer 

 less likely to become sticky or lumpy, or to supply nitrogen from 

 material that would otherwise be wholly thrown to waste. The use 

 of 'conditioners' for the former purpose is, in itself, desirable rather 

 than objectionable; but becomes obnoxious and unjust wheu the 

 nitrogen they contain in unavailable form is made the ba.^^io of a 

 charge at high rule to the buyer. The use also of low-grade and 

 therefore cheap nitrogen supplies whose nitrogen has, by chemical 

 treatment, been made useful for plant-food, is laudable provided the 

 materials are sold for what they are. 



In cases where the inactive insoluble nitrogen forms a large frac- 

 tion of the total nitrogen, and is marked by the index 'c,' and where 

 also the guaranty does not exceed the available nitrogen by an amount 

 equal to most of the 'inactive,' and the selling price, corrected for 

 freight difference, is not considerably less than that asked for fertili- 

 zers of like general composition but supplying nitrogen derived from 

 high-grade goods such as bear the index 'a' or even 'b' there is reason 

 to believe that the buyer is being subjected to unfair treatment. 



Section 1 of the Fertilizer Law of 1909 requires that the guaranty 

 for a fertilizer shall state 'the percentage such fertilizer contains of 

 nitrogen in an available form.' It is, however, by no means clear 

 that the term 'available,' as used in the law, means precisely the 

 same thing that is meant by the term when used to designate the 

 sum of water soluble and active insoluble nitrogen, as determined 

 by the present method. For some nitrogenous fertilizer ingredients 

 always regarded as of high grade, such as dried blood, meat tankage, 

 and cottonseed meal, contain a considerable fraction of inactive insol- 

 uble nitrogen when examined by this method. Until further notice, 

 therefore, the law will not be construed to require that the amount 

 of nitrogen guaranteed shall not exceed that present in a form that 

 will appear as 'available' by the alkaline permanganate method now 

 in use. 



In many of this season's samples, however, the quantity of nitro- 

 gen thus available is found equal to the percentage guaranteed. On 

 the average, the 'available' nitrogen found was 1.59 per cent., the 

 total, 1.95 that guaranteed, 1.82 per cent. 



