MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 



43 



solution more of every ingredient than the four poorer soils 

 did. With 50 tons per acre the amounts of potash are the 

 same in both groups and the stronger soils have yielded less 

 phosphoric acid, but, for the other ingredients, more than the 

 poorer soils. Where 100 tons of manure have been applied the 

 stronger soils have yielded less of both potash and phosphoric 

 acid but more of all other ingredients ; and practically the 

 same can be said of the soils where 200 tons of manure per 

 acre have been applied. 



If the amounts of the different ingredients which were re- 

 covered from the soils to which no manure was added are sub- 

 tracted from the amounts which were recovered from the soils 

 to which the different amounts of manure were added, the dif- 

 ference will show the effect of the stable manure upon the 

 salts which may be recovered from these soils with water alone, 

 65 days after the manure has been applied. The next table 

 gives these results. 



Amounts of salts which manured soils yield to distilled water more 

 than the same soils do unmanured. 



From this table it appears that 25 tons of fresh cow manure 

 applied to the four stronger soils yields in readily water-soluble 

 form after 65 days, 4.27 parts per million of the dry soil more 



