Effect of asparagin on absorption and growth in wheat* 
J. J. SKINNER AND J. H. BEATTIE 
(WITH PLATE 33) 
For the past few years a survey of the organic matter of the 
soil from the standpoint of biochemistry, has been under way 
in the Laboratory of Soil Fertility Investigations. As many 
as 25 different organic compounds have been isolated and 
identified. The definite recognition of these compounds has 
led to a fuller understanding of the chemistry of the organic 
Matter of soils and of the biological changes taking place therein. 
The compounds isolated cover a wide range of chemical substances 
of biological origin. They are represented by the hydrocarbons, 
Consisting of carbon and hydrogen only; by the acids, fats, resins, 
alcohols, esters, waxes, consisting of carbon, hydrogen, and oxygen; 
as well as by a large group of nitrogenous compounds, which 
Consist of carbon, hydrogen, oxygen, and nitrogen. 
The nitrogenous soil constituents isolated are creatinin,t with 
the Probability that creatin also exists, hypoxanthin, xanthin, 
guanin, adenin, cholin, histidin, arginin,t nucleic acid,$ and 
Picolin carboxylic acid.|| A number of these have been studied 
a5 regard to their effect on plant growth. Some of the soil con- 
stituents have been found to be harmful as for instance, picolin 
* Contribution from the Laboratory of Soil Fertility Investigations. | Published 
Y Permission of the Secretary of Agriculture. 
t rey, Edmund C. The isolation of creatinine from soils. Jour. Amer. 
hem. Soc. 34:99. 1912; also U. S. Dept. Agr. Bur. Soils Bull. 83': 11-22. 1912. 
t Schreiner, O., and Shorey, Edmund C. Chemical nature of soil organic 
: S. Dept. Agr. Bur. Soils Bull. 74: 34-36. 1910; The presence of arginine 
ney histidine in soils. Jour. Biol. Chem. 8: 381. 1910; Pyrimidine derivatives and 
- Jour. Biol. Chem. 8: 385. 1910. 
§ Shorey, Edmund C. Nucleic acid in soils. Science II. 35: 390. 1912; Bio- 
M. a: 104. rorr, 
| Schreiner, O., and Shorey, Edmund C. The isolation of picoline carboxylic 
Feng soils wag its relation to soil fertility. Jour. Amer. Chem. Soc. 30: 1295. 
Sole Ban ‘solation of harmful organic substances from soil. U.S. Dept. Agr. Bur. 
* 53: I-53. 1909. 
| 
acid 
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