﻿AGRICULTURAL UTILIZATION OP ACID LANDS. 13 



There is one other feature of the acid-soil question which merits 

 the serious consideration of agriculturists. Recent investigators 

 have shown that various fungi are able to fix and feed upon the 

 nitrogen of the atmosphere, just as do the bacteria of the clover root 

 tubercles and certain free bacteria of alkaline and neutral soils. One 

 Swiss investigator, Charlotte Ternetz, has isolated from acid soils 

 several fungi in which this faculty not only occurs but is developed 

 to a high degree of efficiency. It has not yet been fully demon- 

 strated that true mycorhizal fungi possess this faculty of nitrogen 

 fixation, but there is much evidence that they do. Should this be- 

 come definitely established, agriculture must recognize in the" my- 

 corhizal fungi a direct and powerful means 6f adding to the store 

 of available nitrogen, and the culture of mycorhizal plants in acid 

 soils will have a significance far beyond the mere value of the crops 

 produced by them. 



CONCLUSION. 



In closing this paper the writer desires to impress on agricultural 

 investigators (1) that soil acidity is not always an objectionable 

 condition which invariably requires an application of lime, (2) that 

 under certain economic conditions a complete system of acicl-land 

 agriculture is practicable and desirable, and (3) that the extent to 

 which our cheap eastern acid lands can be utilized with small appli- 

 cations of lime, or under some conditions without its use, is a legiti- 

 mate and important subject for detailed investigation, from which 

 may reasonably be expected results of far-reaching economic im- 

 portance. 



ADDITIONAL COPIES of this publication 

 A may be procured from the Superintend- 

 ent of Documents, Government Printing 

 Office, Washington, D. C, at 5 cents per copy 



WASHINGTON : GOVERNMENT PRINTING OFFICE : 1913 



