98 CHARLES B. LIPMAN 



Wildt^^ reaches the conclusion that these reported investigations 

 do not demonstrate the need of a definite hme-magn^sia ratio, 

 It is not denied that some relatipn may exist between some such 

 ratio and plant growth, but that the evidence extant does not 

 support such a view. 



In the investigations later carried out by Lemmermann, 

 Einecke and Fischer" and by Lemmermann, Foerster and 

 Einecke^^ no support was found for Loew's lime-magnesia ratio 

 hypothesis. In the first paper cited results are given of a large 

 number of experiments carried out during 1907, 1908 and 1909, 

 with six soil types and with eight different crops. The effects 

 on both plants and soil bacteria were studied. No effects were 

 noted so far as the yields were concerned with variations within 

 wide limits in the proportion of lime to magnesia in the soils 

 mentioned. Different plants varied considerably in their be- 

 havior to lime and magnesia. Sometimes improvement was 

 noted following upon the application of lime and magnesia, even 

 when those materials were found in the soil to a very slight extent 

 for example, a few hundredths of 1%; sometimes no improve- 

 ment was noted. Lime, magnesia, and phosphoric acid in their 

 content in plants varied greatly with substantially the same 

 yield of crop. In passing, it may be added that as in the case 

 of higher plants no distinct relationship between lime and mag- 

 nesia could be estabUshed as particularly favorable to the soil 

 bacteria. 



In the second pubhcation above cited ''there was no constant 

 relation" found "between the hme assimilated by plants and 

 that soluble in the soil solution." Only 4% of the hme in the 

 soil solution was absorbed and about 5.6% of the lime fertihzer. 



In 1912 Gile began the pubhcation of a series of papers which 

 have made a notable contribution to the subject here under 

 consideration. In the first paper^^ the relation of calcareous 



'^ Cultura, vol. 18, p. 463, 505, 557, 650. Cited from E. S. R., vol. 18, p. 532, 

 1906-07. 



" Landw. Jahrb., vol. 40, p. 173. Cited from E. S. R., vol. 25, p. 725, 1911. 

 '» Landw. Jahrb., vol. 40, p. 255. Cited from E. S. R., vol. 25, p. 725, 1911. 

 ^' Porto Rico Agr. Exp. Sta. Bui. 11, 1912. 



