A CRITIQUE OF THE HYPOTHESIS OF THE LIME- 

 MAGNESIA RATIO 



CHARLES B. LIPMAN 



University of California, Berkeley, Cal. 



II 



THE INDIFFERENT INVESTIGATIONS OR THOSE OF NEITHER 



POSITIVE NOR NEGATIVE SIGNIFICANCE ON THE QUESTION 



OF THE LIME-MAGNESIA RATIO 



Numerous experiments have been carried out by many inves- 

 tigators which deal as do some of Loew's earher investigations, 

 more specifically with the functions of lime and magnesia inde- 

 pendently in plant growth, and also with such matters as the 

 relationship of lime and magnesia, each alone to other nutrients 

 in the medium in which the plant is grown. Some of these may 

 have direct bearings on the lime-magnesia ratio, but not as clearly 

 as those which are above re\dewed. For that reason, a number 

 of the typical^ ones, and perhaps most of them which are of inter- 

 est, are here briefly reviewed for use by those who are interested 

 in the question. 



T. H. Kearney and F. K. Cameron^'* made a study of the effect 

 of certain components of alkah soils upon seedling plants. 

 Their results, dealing principally with culture solutions, made it 

 quire clear that calcium and magnesium could antagonize each 

 other, and further that they could each antagonize toxic effects 

 of other salts. 



Ulbricht, in 1894, carried out some investigations which were 

 published in two papers. The first" dealt with a study of the 

 action of hme and magnesia in marl and burnt lime. Ulbricht 

 apphed 710 pounds per acre of burnt hme which was poor in 



5*U. S. D. A. Rpt., no. 71, p. 7-60, 1902. 



" Chem. Ceiitb. 1894, vol. 2, p. 803. Cited from E. S. R., vol. 6, p. 628, 1894-5. 



119 



THE PLANT WORLD, VOL. 19, NO. .5, 1916 



