54 



T. Lyttleton Lyon and James A. Bizzell 



CALCIUM-MAGNESIUM RATIO 



In the soil that was placed in the lysimeter tanks the calcium-magnesium 

 ratio was approximately as given in table 39: 



TABLE 39. Calcium-Magnesium Ratio in Soil 



The ratio of calcium to magnesium that obtains in the drainage water 

 is very different from that in the soil. Thus, in the water that percolated 

 thru the soil which received no fertilizer and no lime, the calcium- 

 magnesium ratio was 5.4 to 1. This is a much wider ratio than that 

 found in the soil itself, and in this solution the magnesium is not in 

 sufficiently large proportion to exert any toxic action on plant growth, 

 while in the upper three feet of soil the ratio is sufficiently narrow to 

 menace vegetation were these ingredients equally soluble. 



The effect of the lime application to this soil was to narrow the ratio 

 in the drainage water, reducing it to 4.4:1. This is the average for the 

 drainage from the four tanks treated .similarly to the four mentioned 

 above except for the application of lime. Instead of increasing the 

 proportion of calcium in the drainage water, the effect of liming is to 

 decrease it. How far this would go with greater applications of lime 

 could not be ascertained from these experiments. 



The greater solubility of calcium as compared with magnesium in 

 soil water makes it possible to farm soil with a narrower calcium-magnesium 

 content than would be tolerated by plants if the salts were in solution. 

 Applications of moderate quantities of lime apparently have little effect 

 on this ratio in ordinary soil, but if the soil contained a large excess of 

 magnesium over calcium it is conceivable that the application of lime 

 might, by liberating magnesium, be detrimental to crop growth. 



REMOVAL OF POTASSIUM 



Of the bases studied, potassium was removed in greatest quantity 

 by the crops and, with the exception of magnesium, in least amount by 



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