MOVEMENTS OF SALTS IN SOILS. 



83 



the bottom layer was greater than at any other level except 

 that of the surface inch, .and also that at the end of 50 days 

 more potash was recovered than was recovered at the end of 20 

 days. Between the 18 to 20 inch level and the 3 to 4 inch level 

 less potash could be recovered from the soil than before the cap- 

 illary movement had taken place, indicating that these layers 

 had been washed and the potash moved on into the layers above. 



0-1 /-Z 1-3 



unt 



in- 



St6f 



FIG. 3. Showing distribution of water-soluble potash after capillary movement. 

 Solid line indicates results after fifty days ; broken line after 20 days. Val- 

 ues are means for 8 soil types. 



The mean amount of potash recovered from the surface inch 

 at the close of the 50 days was 82.38 parts per million of dry 

 soil. Taking the mean weight of a cubic foot of soil at 73.36 

 Ibs., as given in Bulletin "C", "Relation of Crop Yields 

 to the Amounts of Water-Soluble Plant Food Materials Recov- 

 ered from Soils," p. 51, this accummulation of potash is equiva- 

 lent to about 22 Ibs. per acre in the surface inch of soil. 



