THE LIME-MAGNESIA RATIO 95 



tion is made on the ground that the secondary potassium phos- 

 phate reduced the injurious effects of an excess of magnesium. 

 It is seen here that Loew admits inferentially the efficacy of 

 other factors than the calcium and magnesium to carry out an- 

 tagonistic effects. This point will, however, be discussed more 

 fully below. 



Dojarenko-^ prepared a statement based on experimental work 

 in the field with reference to Loew's hypothesis on the role of lime 

 in soils. The results obtained by this investigator show that the 

 beneficial effect of lime can not entirely be due to its antagonism 

 for an excess of magnesia. The marked benefit obtained with 

 lime applications, with oats, for example, on soils already con- 

 taining more than enough to neutralize the effects of magnesia 

 according to Loew's hypothesis, would seem to offer proof in 

 that regard. 



Meyer has published at least two papers which deal with the 

 question of the lime-magnesia ratio. The first one^^ reports in- 

 vestigations of different forms of hme and magnesia, and the 

 second^" further experiments with lime and magnesia. In the 

 first, pot experiments were carried out in which no very close 

 relationship could be noted between the maximum yields ob- 

 tained and the ratio of lime to magnesia existing in the soil. It 

 is true that wherever an insufficient amount of hme is present 

 the yield can be increased by applying either lime or magnesia. 

 The lime requirement is determined by ascertaining the amount 

 of lime in the soil and serves as a useful guide except in soils 

 which are very rich in magnesium carbonate. It was found 

 that applications of magnesia lowered the Hme content of the 

 plant and raised the magnesia content thereof. With lime ap- 

 plied, the reverse was found to be true. With the different 

 plants tried in the investigations, there appears to be a great 

 diversity in behavior toward an excess of magnesia. In the later 

 experiments above cited, the work was again carried out in pots 

 with clay loam, sand, and loam as culture media. When in 



^* Russ. Jour. Exp. Landw., vol. 4, p. 183. 



2' Landw. Jahrb., vol. 33, p. 371. 



'» Landw. Jahrb., vol. 39, p. 254. Cited from E. S. R., vol. 23, p. 134, 1911. 



