May, '14] 



GRANITIC SOIL POTASSIUM. 

 Fid / 





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# H ny 



The plots from which these data were secured were not ferti- 

 lized and were located on heavy clay soil. Moisture conditions 

 also were very favorable as the large yields show.' Later data 

 indicate that only under the most favorable conditions will the 

 crop absorb such a high per cent, of potassium oxide. The re- 

 lation between yields of hay and the amounts of potassium oxide 

 removed shows clearly that, as yields increased, the potassium 

 oxide taken up increased proportionately. These observations 

 cover a fairly wide range of yields and show that these soils can 

 supply enough soluble potassium to produce good crops. 



When the observations are extended to soils of lighter character, 

 where no fertilizers have been used, the amount of potassium re- 

 moved by the crop is still proportional to the yield. However, 

 the relative amount removed is not so great as is removed from 

 the heavier soils. The data in Table II show the yield, per 

 cent, of potassium oxide and the amount of potassium oxide 

 removed. 



