96 CHARLES B. LIPMAN 



these soils correction was made of the excess of magnesia, reduced 

 yields of both buckwheat and oats followed. When magnesium 

 sulphate, magnesium chloride and sodium chloride were applied 

 to soils with a high magnesia content, they gave increased yields 

 with cereals, though not with hoed crops and the forage plants. 

 Both calcium carbonate and magnesium carbonate slightly in- 

 creased the yield of red clover, mustard and potatoes on an acid 

 soil deficient in lime, whereas gypsum reduced the yield. 



Meyer's investigations are called in question by Loew^^ on the 

 ground that too many plants were grown in one pot to allow of 

 normal conditions for growth and that the plants were harvested 

 in the blooming stage instead of being allowed to mature. He 

 quotes the experiments of other investigators which are above 

 reviewed in support of the contention that the lime-magnesia 

 ratio is an established fact. 



In more detailed and careful work than that carried out by 

 most investigators, Konovalov,^^ in a large series of sand and 

 water culture experiments, shows that sand cultures with a nu- 

 tritive solution supplied increase in producing capacity for both 

 millet and oats vnth the increase in the supply of lime, the quan- 

 tity of magnesia remaining throughout constant. This remains 

 true until the ratio of lime to magnesia is as 6.7: 1. Beyond this 

 ratio, or when the lime is proportionately higher than therein 

 indicated, the yield of millet is somewhat decreased and that of 

 barley considerably decreased. In further sand cultures with 

 barley, likewise, no support for a definite lime-magnesia ratio 

 was obtained. In his water culture experiments Konovalov 

 found that the best yield of barley and maize was obtained wdth 

 a ratio of 3.3: 1 and 0.8: 1 respectively for the yields of above 

 ground parts and total yields. So far as the root yields of bar- 

 ley were concerned, the best ratios were respectively 6.7: 1 and 

 13.3: 1; and for corn roots 3.3: 1. 



In later investigations^^ by the same experimenter, which were 



" Landw. Jahrb., vol. 39, p. 1005. Cited from E. S. R., vol. 24, p. 716. 1911. 



"Russ. Jour. Expt. Landw., vol. 8, p. 257. Cited from E. S. R., vol. 19, 

 p. 827, 1907-08. 



" Russ. Jour. Expt. Landw., vol. 10, p. 303. Cited from E. S. R., vol. 22, 

 p. 433, 1910. 



