MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 



55 



could be recovered from the four soils by washing them in dis- 

 tilled water during three minutes, as shown by determination 

 before and after the crops had occupied the ground ; the results 

 appear in the table which follows: 



Amounts of water-soluble xalts in the surface foot, under corn, at the 

 beginning and close of the growing season. 



There is thus shown, in each of the four cases, that a reduc- 

 tion has occurred in the amounts of potash which) could be 

 recovered from these soils at the close of the season,, and this 

 reduction was not confined to the surface foot, as will appear 

 from the next table: 



Changes in the amounts of potash which could be recovered from the 

 surface three feet of four soils after cropping one season. 



