TOXICITY AND ANTAGONISM OF VARIOUS ALKALI 
SALTS IN THE SOIL* 
By F, S. 'Ra.kvcls, formerly Director, M. D. Thomas, Associate in Agronomy, and D. W. 
Pittman, Instructor in Agronomy, Utah Agricultural Experiment Station^ 
In the studies of soil alkali which have been carried out at the Utah 
Station (4, 5) ^ during the past 10 years, a large number of the factors 
which influence the toxicity of most of the commonly occurring alkali 
salts have been correlated. It has been frequently noticed, however, 
that the toxicity of a mixture of salts in a soil seems to be the sum of the 
separate toxicities of the constituents of the mixture, and since these 
observations are at variance with the marked antagonistic action of the 
same salts in solution cultures a more detailed study of this question has 
been undertaken. 
The experiments described in this paper were planned to show the 
influence on plant growth of adding other salts, as well as acids and 
manure, to a soil already impregnated with sodium carbonate. The 
possibility of finding a marked antagonism between some of these added 
substances and ‘‘black alkali” was an incentive to make the scope of the 
investigation as broad as possible. Since the results from this point of 
view, however, are largely negative the data are presented as a contri¬ 
bution to the literature on the toxicity of mixtures of alkali salts. Some 
preliminary work has also been done on soils impregnated with sodium 
chlorid and sodium nitrate instead of sodium carbonate. 
REVIEW OF THE UTERATURE 
Experiments conducted by Kearney and Cameron (6) were among the 
first to show the ameliorating effect of adding a second alkali salt to a 
solution which was already toxic to plants. In their work the plants 
were germinated while not in contact with the alkali salts, and the roots 
were then held in the solution for 24 hours. The toxicity of the solution, 
was determined by slight injury to the root tips. The toxic concentra¬ 
tions were not proportional to the concentrations which absolutely pre¬ 
vented growth of the plants, and the toxicity of the salts exchanged 
places somewhat when the absolute rather than the minimum check in 
growth was considered. Very small quantities of salts caused slight 
injury to the roots. The addition of a second cation to a toxic solution 
was found to reduce the toxicity of the solution more than the addition 
of a second anion. Sodium in most combinations greatly weakened the 
toxic action of magnesium. Calcium, especially in the form of the 
sulphate, markedly counteracted the injurious effect of either sodium or 
magnesium ions. Calcium sulphate was much more beneficial to the 
sulphates of sodium and magnesium than to their chlorids. A very 
1 Accepted for publication July II, 1922. 
* The authors wish to express their appreciation to Mr. N. I. Butt for his help in calculating and tabulat¬ 
ing the data presented in this paper. 
® Reference is made by number (italic) to “ Literature cited,” p. 337”338 
Journal df Agricultural Research. 
Washington, D. C. 
acd 
(317) 
Vol. XXIV. No. 4 
Apr. »8, 1923 (. 
Key No. Utah-17 
