3i8 
Journal of Agricultural Research 
Vol. XXIV, No. 4 
effective neutralization of sodium carbonate injury was found when 
calcium chlorid was added to the solution. 
The work of Miyake(7j) with rice in cultures of magnesium sulphate, 
magnesium chlorid, calcium chlorid, sodium sulphate, and sodium 
chlorid showed that while N/jo solutions of the individual salts were 
toxic, when two of these solutions were mixed in certain proportions 
the toxic effect was more or less neutralized. The greatest neutraliza¬ 
tion of toxicity was observed when calcium chlorid was added to mag¬ 
nesium sulphate or chlorid. Some antagonism was also noticed between 
chlorids and sulphates of sodium and magnesium, as well as between 
potassium chlorid and magnesium or calcium chlorid. In a study of 
the antagonism between sodium and potassium, the salts—sodium 
nitrate, potassium chlorid, potassium nitrate, sodium chlorid, potassium 
sulphate, and sodium sulphate—^were used. The antagonistic action 
of the cations on each other was much greater than that of the anions. 
The greatest antagonism between sodium and potassium usually oc¬ 
curred when one part of one N/io solution was mixed with four parts 
of another. 
Osterhout(72) found that antagonism between sodium chlorid and 
potassium chlorid was greater when one of the salts predominated in 
the solution than when both were present in nearly equal quantities. 
Small quantities of ammonium chlorid, magnesium chlorid, or calcium 
chlorid reduced the toxicity of either potassium chlorid or sodium 
chlorid, but with calcium chlorid even larger quantities were beneficial. 
Kearney and Harter(7) tested the tolerance of eight different kinds of 
plants to solutions of sodium and magnesium salts and found that cal¬ 
cium sulphate greatly diminished the toxicity of the salts, especially 
magnesium. Calcium sulphate changed the order of toxicity of the 
solutions. . ^ 
Hansteen(j), working with wheat seedlings, has found that calcium 
compounds exert a beneficial effect on the toxicity of solutions of alkali 
salts. 
A comparison of soils and solutions by Harris(4) showed the antago¬ 
nism between the common alkali salts to be more pronounced in solu¬ 
tion cultures of wheat seedlings than in loam soils. In fact the only 
consistent case of antagonism observed in soil seems to have been with 
the nitrates of potassium, sodium, and magnesium at 4,000 parts per 
million (4, p. 46). _ .. . m 
Some of the most positive antagonistic results in soils have been 
secured by measuring the activity of soil bacteria. By this means it 
has been shown by different experimenters that there is antagonism 
between anions as well as between cations of the salts common in alkali 
soils. This work has been so well summarized in a paper by Greaves(2) 
that the reader is referred to this publication for a review of this phase 
of the subject. . ^ m t • ^ 
Experimenting with barley growing on a clay-adobe soil, hipman ana 
Gericke(<^) found antagonism between sodium chlorid and sodium sul¬ 
phate and between sodium chlorid and sodium carbonate in the second 
crop, though there was no antagonism shown between these salts in the 
crop* grown soon after the salts had been added. A slight antagonism 
was noticed between sodium carbonate and sodium sulphate in the 
first crop. A marked antagonism between sodium sulphate and cal¬ 
cium sulphate was apparent in both the first and second crops. 
