THE LIME-MAGNESIA RATIO 131 



also be interested in noting the rather extensive bibliography- 

 given by Hansteen in the paper under discussion. 



Viewing the question of the Hme-magnesia ratio hypothesis in 

 its practical aspects and bearings, one is at once impressed with 

 the hopelessness in general farming particularly, of attempting 

 to maintain a proper lime-magnesia ratio in soils. Assuming 

 that Loew's necessaiy ratios for different groups of plants are 

 correct, and assuming further that we should have to grow a 

 series of crops, as Meyer points out, like buckwheat, barley, oats 

 and legumes, in rotation, we should have to be constantly chang- 

 ing the ratio of lime to magnesia in a given piece of land from 

 season to season so as to accommodate the lime-magnesia ratio 

 conditions therein to the particular crop which we are growing. 

 How thoroughly infeasible such a scheme would be is evident to 

 anyone without discussion. If we consider, moreover, that we 

 were growing orchard crops, the trees of which had a certain 

 hme-magnesia ratio very far different from the annual crop, and 

 then that we tried to grow intercalary crops between the trees, 

 we should have to change at one and the same time, very prob- 

 ably, in accordance with Loew's idea, two different ratios of 

 hme to magnesia which might vary as much as 4: 1 or 5: 1, down 

 to 1:1, which is the ratio given for oats by Loew. In practice, 

 therefore, any attention to the lime-magnesia ratio would seem 

 to be quite out of the question even if it were proved that the 

 hme-magnesia ratio for specific plants must necessarily be kept 

 at a certain point. 



Wholly irrational as it may seem from the foregoing statements 

 to attempt changing the lime-magnesia ratios in field soils by 

 either applications of calcium or magnesium salts, it has none the 

 less been attempted to a considerable degree in this state, and 

 the writer has known of as much as forty tons of gypsum per 

 acre having been applied to citrus soils for the purpose of bring- 

 ing up a proper relationship between calciimi and magnesium 

 compounds in that soil to meet a supposed optimum ratio for 

 the citrus trees. Needless to say, such applications have never 

 met with favorable results, and considering other disadvantages 

 about gypsum, we can readily see how some of them might meet 

 with very unfavorable results. 



