

3 88 



BOTANICAL GAZETTE 



[may 



7. The process of oxidation is usually accelerated by the addition 



- 



of sodium nitrate to an aqueous soil extract. The addition of other 

 fertilizer salts also influences oxidation. 



8. The process of oxidation by roots is largely, if not entirely, 

 due to the activity of a peroxidase produced by the roots. This 

 oxidizing enzyme is most active in neutral or slightly alkaline solu- 

 tions. The activity of the enzyme may be inhibited by the presence 

 of acid and also by the conditions in solutions where anaerobic pro- 



cesses occur. 



Agricultu 



Washington, D. C. 



t * 





