EXPERIIVIENTAL STUDY OF THE EFFECT OF SOME 

 NITROGENOUS SOIL CONSTITUENTS ON GROWTH. 

 NUCLEIC ACID AND ITS DECOMPOSITION PROD- 

 UCTS' 



A Contribution from the Laboratory of Fertility 

 Investigations 



OSWALD SCHREINER and J. J. SKINNER 

 Bureau of Soils, Department of Agriculture. Washington. D. C. 



NUCLEIC ACID 



Nucleic acid has been found to be a constituent part of the 

 soil organic matter in the course of the investigations carried on 

 in this laboratory. When it occurs it forms a constituent part 

 of the so-called humus, precipitated by the addition of acid to 

 an alkaline extract of soils. Its method of separation and identi- 

 fication is described elsewhere.' 



Nucleic acid is a common constituent of plant and animal 

 material and its source in the soil is doubtless due to its accumu- 

 lation from vegetable and animal debris and from the bodies of 

 the microorganisms of the soil, the bacteria, the molds, the pro- 

 tozoa, etc. Chemically it is a complex substance, capable of 

 being split into much simpler units, such as phosphoric acid on 

 the one hand, and nitrogenous compounds on the other, such as 

 the purine and pyrimidine compounds, hypoxanthine, xanthine, 

 adenine, guanine and cytosine, all of which have been found in 

 soils in the course of these investigations, as well as carbohydrate 

 units, such as pentose sugars, likewise found in soils. 



In addition to these ultimate units of degradation, there exist 

 the intermediate combinations, such as pentose sugar-purine base 

 complex, and other combinations of the above constituent parts. 



' Published by permission of the Secretary of Agriculture. 



- Shorey, E. C., Bull. 88, Bureau of Soils, U. S. Dept. of Agric. 1912. 



45 



THE PLANT WORLD, VOL. 16, NO. 2, FEBR0ARY, 1913 



