58 



T. Lyttleton Lyon Ax\d James A. Bizzell 



TABLE 44. Potassium in DRAI^fA3E Water from Tanks with Larger and with 

 Smaller Quantities of Potassium in the Crops 



Tanks 



Potassium 

 in crops 

 (pounds) 



Potassium 

 in drainage 



water 



(parts per 



million) 



3, 5, 7, 9. 

 6, 10... 



89.0 

 58.2 



12.5 

 12.4 



It would seem that the amount of potassium in the drainage water 

 is more or less independent of the quantity used by the crops. To what 

 the greater solubility of potassium in the planted soil is due does not 

 appear from these results. If the soil solution were concentrated with 

 respect to potassium, it might be conceived that removal of potassium 

 from solution by crop growth was soon made good by further solution 

 of potassium from the soil, and that the soil solution would thus be kept 

 at a uniform concentration; but the difference in the concentration of 

 the drainage water from the planted and from the bare soil would not 

 admit of this hypothesis. 



Effect of lime on removal of potassium 



The application of lime to this soil did not result in any increase in 

 the quantity of potassium contained in the drainage water or in the amount 

 removed by the crops. This is shown by table 45. It has been so often 



TABLE 45. Average Annual Removal of Potassium from Limed and from 



Unlimed Tanks 



(In pounds per acre) 



58 



