Lysimeter Experiments 



59 



stated that potassium is liberated by the appHcation of hme, that it is of 

 interest to note any indication of such action that may be derived from 

 the composition of the drainage water. If the apphcation of hme to this 

 soil liberated any potassium, it must have been absorbed by the lower 

 layers of soil and thus did not appear in the drainage water. While there 

 is no indication that potassium was set free by the lime treatment, it is 

 quite probable that if this had been the case the potassium would have 

 been absorbed by the lower soil, for the application of a potassium salt 

 did not result in increasing the quantity of potassium in the drainage 

 water. 



The effect of the lime treatment on the concentration of potassium 

 n solution in the drainage water, with respect both to the percolate 

 from the planted soil and to that from the unplanted soil, is shown in 

 table 46. It cannot be concluded from these figures that the application 

 of lime results in increasing the concentration of potassium in the drain- 

 age water. 



TABLE 46. Potassium in Drainage Water from Limed and from Unlimed Tanks 



Tanks 



Soil treatment 



Potassium 



(parts per 



million) 



3, 5, 6. 

 7, 9, 10 



4 



8 



Not limed, cropped 

 Limed, cropped . . . 

 Not limed, bare. . . 

 Limed, bare 



12.0 



12.9 



12.2 



9.1 



Altho the drainage water showed no evidence of liberation of potassium 

 by lime, the possibility still remained that a greater removal of potassium 

 from the limed soil by plants would prevent the appearance in the drainage 

 water of that set free. As the potassium content of the crops raised 

 on these tanks for four years had been determined, a comparison was 

 made between the quantity of potassium removed by the plants that 

 grew on the limed so Is and the amount removed by the plants on the 

 unlimed soils, and also of the percentages of potassium in the crops. 

 The results are given in table 47: 



59 



