2 
Journal of Agricultural Research 
Vol. V, No. i 
possible in all cases to determine how well crops will grow in a soil of 
known alkali content. 
In view of the great practical importance of the subject as well as its 
scientific interest, considerably more information should be gathered on 
the relation of alkali in soils to crops. The limits of endurance of each 
crop for each salt in the different kinds of soil should be fixed with much 
greater exactness. 
It was in response to this need that the work reported in this article 
was undertaken. 
REVIEW OF THE LITERATURE 
The effect on plants of the salts classed as alkali has been the subject 
of much investigation, but the greater part of this work has been done in 
solution cultures rather than in the soil. By using water cultures an 
attempt has been made to limit the great number of factors that exist 
in the soil, where some of the salts are neutralized and others are absorbed. 
The work of Loew (16), 1 Kearney (12-14), Harter (7, 14), Cameron 
(5, 13), Breazeale (1-2, 5), Dorsey (6), Osterhout (20-21), True (26), 
McCool (18), and others in this country and numerous workers in Europe 
has added many facts to our knowledge of the action of single salts and 
balanced solutions on plants grown in water cultures. These workers 
have shown the great toxicity of salts like magnesium when used alone 
in a water culture and how this toxicity may be reduced by the presence 
of other elements. 
The facts obtained in these experiments have increased our knowledge 
of plant physiology and the fundamental nature of alkali; but conclu¬ 
sions drawn from them should not be too definitely applied to the action 
of alkali as it is found in the soil. 
For example, in solution cultures the salts of magnesium when present 
alone are very toxic, while if added to a normal soil they are no more 
toxic than a number of other salts. Again, Kearney and Cameron (13) 
concluded from their work with solutions that “the toxic effect of inju¬ 
rious salts is due very much more to the influence of the cathions (derived 
from the basic radicle) than to the anions (furnished by the acid radicle).” 
This may be true for solution cultures, but it certainly does not always 
hold for salts added to soils, as the results in the present paper will 
show. 
It is desirable, therefore, in studying the effect of soil alkali on plants 
to use soil as a medium in which to grow the plants, even though it is 
somewhat difficult to watch all the factors involved. 
In 1876 Toutphoeus (9), and Henri Vilmorin (9) about the same time, 
published results of experiments showing that chemical fertilizers when 
added to the soil in too large quantities inhibit the germination of 
seeds. 
1 Reference is made by number to “ Literature cited,” p. 52-53. 
