JOIMAL OF AGRICETIML ISEARCH 



Vol. XVI Washington, D. C, January 27, 191 9 No. 4 



INFLUENCE OF SALTS ON THE NITRIC-NITROGEN 

 ACCUMULATION IN THE SOIL 



By J. E. Greaves, Chemist and Bacteriologist, E. G. Carter, Assistant Bacteriologist, 

 and H. C. Goldthorpe, Assistant Bacteriologist, Department of Bacteriology, Utah 

 Agricultural Experiment Station 



INTRODUCTION 



Salts which may occur in soils and those applied to them in various 

 operations influence the number, species, and actixaty of the microflora 

 of a soil. These factors are in turn reflected by the yields obtained from 

 the soil. Some substances applied to a soil serve as food for the growing 

 plant; others increase plant growth but not through the direct furnishing 

 of food. This latter effect may be due to a change brought about by the 

 salt on the physical, chemical, or bacterial properties of the soil. The 

 substance may alter the physical properties of the soil to such an extent 

 that the bacterial flora is modified ; this in turn may increase or decrease 

 the crop produced upon the soil. Other substances may react chemi- 

 cally with constituents within the soil and in so doing liberate substance 

 which can be directly utilized by the growing plant. Again, they may 

 directly modify the microflora and fauna of the soil both as to numbers 

 and physiological efficiency. Or, in some cases, all three changes may 

 be wrought by one and the same salt. The question therefore arises as 

 to what effect this or that fertilizer or soil amendment is going to have 

 upon the bacterial activities of the soil. 



Furthermore, there are millions of acres of land in arid America which 

 contain varying amounts of soluble salts. Some of these soils contain 

 such large quantities of these so-called "alkaUs" that no vegetation is 

 found upon them. Other soils contain onl}^ a medium amount of soluble 

 salts, and the vegetation is composed chiefly of alkali-resisting plants. 

 Still other soils contain much smaller quantities of soluble salts, and 

 they become injurious only when the soil is improperly handled. The 

 reclaiming of the heavily charged soils and the maintaining of the others 

 in a productive condition can be carried on successfully only when we 

 understand the influence of salts upon the growing plants and their action 

 upon the biological, chemical, and physical properties of the soil. 



The purpose of this investigation is therefore to determine the relative 

 toxicity of various substances found in or applied to a soil, as measured 

 in terms of bacterial activities of the soil; also to determine the stimu- 



Jouraal of Agricultural Research, Vol. XVI, No. 4 



Washington, D. C. Jan. 27, 1919 



qz jQy Key No. Utah-io 



