THE LIME-MAGNESIA RATIO 97 



intended as a continuation of his former work, similar methods 

 were employed with water and sand cultures of wheat, lupines, 

 Setaria italica and oats. The results with these confirmed Kono- 

 valov's former results. Magnesia alone was found to be injuri- 

 ous to plants and the yields were found to increase with the in- 

 crease in the hme content of the culture medium. In brief, 

 the author is of the opinion that the results do not lend any sup- 

 port to, and probably deny Loew's view that there is a definite 

 lime-magnesia ratio for every plant. 



Somewhat less in the nature of direct evidence against the 

 lime-magnesia ratio hypothesis, are the results of Kossovich and 

 Althausen,^'* These investigators found that barley was bene- 

 fitted by hming and withstood excessive quantities of calcium 

 carbonate quite well. The injurious effects of calcium carbo- 

 nate when apparent, would seem to carry over for the second 

 season. Basic magnesium carbonate was found to be the most 

 injurious of all the materials tried. Unfortunately, there is not 

 sufficient evidence given as to the Ume and magnesia ratios in 

 the soils employed to allow one to appraise in their true light 

 the results just referred to. 



Of similar nature is the statement made by Wheeler and 

 HartwelP^ in which the value of magnesia as a manure is dis- 

 cussed. The authors incline to the opinion that their experi- 

 ments indicate that too much attention has been paid by writers 

 to Lowe's theory in their recoimnendations for the use of mag- 

 nesian limestone. They put forward the unanswered argument 

 that the effects of any such applications might be explained in 

 other ways than by Loew's theory. In general, they do not be- 

 Heve that the state of our knowledge of the subject justifies us 

 in stating what the ratios of lime and magnesia in soils should be, 

 because soils differ very much in all respects. 



In a critical review of all investigations on the subject of Loew's 

 theory regarding the lime-magnesia ratio in soils, Ruijter de 



"Russ. Jour. Expt. Landw., vol. 10, p. 693. Cited from E. S. R., vol. 23, 

 p. 226, 1910. 



» Rhode Island Agr. Exp. Sta. Rpt.. 1904, p. 221. 



