4£Sas bulletin of the 
No. 158 
Contribution from the Bureau of Soils, Milton Whitney, Chief. 
November 10, 1 9 14. 
(PROFESSIONAL PAPER.) 
THE NITROGEN OF PROCESSED FERTILIZERS. 
By Elbert C. Lathrop, 
Scientist in Soil Fertility Investigations. 
INTRODUCTION. 
Organic compounds have lately taken on a deeper significance in 
their relation to the complex problems of the soil and of crop produc- 
tion, for not only do they affect the physical conditions and chemical 
reactions of the soil but they also have been sho^Ti to be directly con- 
nected with fertility or infertility, some of them being essentially bene- 
ficial to the growth of plants, while others are distinctly harmful. 
Of the organic compounds thus far isolated from soils, a large number 
contain nitrogen, and of these nitrogenous substances, some have 
been found rather widely distributed in soils varying as to location, 
climate, methods of cropping, etc. These nitrogenous compounds 
occur either as plant constituents or arise from the decomposition of 
plant or animal protein, brought about by the various biological and 
biochemical agents in the soil. Not only compounds of this class 
found in soils but also many other protein decomposition products 
have been studied, both alone and in conjunction with the three fer- 
tilizer elements, in respect to their action on plant growth, and they 
have been shown in a number of cases to exert a beneficial influence; 
furthermore, these complex compounds are available for use by the 
plant without first being changed by chemical or biochemical means 
into ammonia and then to nitrates.* 
That these facts have an immense practical bearing on fertilizers 
and the fertilizer mdustry, both from the standpoint of the producer 
and of the consumer, is at once obvious. The old high-grade nitrog- 
1 A Beneficial Organic Constituent of Soils: Creatinine. By Oswald Schreiner, E. C. Shorey, M. X. 
Sullivan, and J. J. Skinner. Bui. 83, Bur. SoilS; U. S. Dept. Agr., 1911. 
Nitrogenous Soil Constituents and Their Bearing on Soil Fertility. By Oswald Schreiner and J. J. 
Skinner, Bui. 87, Bureau of Soils, U. S. Dept. Agr., 1912. 
This investigation is a contribution to the knowledge of the nature of the changes brought about in the 
manufacture of some of the processed fertilizers, and of the character and availability of such processed goods 
in mLxed fertilizers when used in farm practice. 
63138°— Bull. 158—14 1 
