50 



T. Lyttleton Lyon and James A. Bizzell 



TABLE 31. Magnesium in Drainage Water and in Crops 

 (Pounds per acre, annual average) 



Effect of plant growth on removal of magnesium 



As in the case with calcium, the quantity of magnesium removed in 

 the crop is small as compared with that lost in the drainage water, but 

 this difference is not so marked as in the case of calcium. 



Another respect in which magnesium is similar to calcium is that the 

 quantity of magnesium in the drainage water of the unplanted soil is 

 greater than that removed from the planted soil by the drainage water 

 and the crops combined. This is brought out by table 32: 



TABLE 32. 



Average Annual Removal of Magnesium from Planted and from 

 Unplanted Tanks 



(In pounds per acre) 



Tanks 



3,5,6,7,9, 10. 

 4,8 



Soil 

 treatment 



Planted . 

 Bare. . . 



Magnesium conserved by cropping. 



Magnesium removed 

 in 



Drainage 

 water 



37.0 

 65.2 



Crops 



7.1 



Total 



magnesium 



removed 



44.1 

 65.2 



21.1 



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