34 



INFLUENCE OF FARM YARD MANURE UPON THE AMOUNTS OF WATER-SOLUBLE 

 SULPHATES IN SOIL. 



The next table shows the amounts of SO 4 which were recov- 

 ered from the 8 soil types after having been in contact with 

 about 25, 50, 100 and 200 tons of manure per acre during 65 

 days. 



Amounts of sulphates, as SO 4 , recovered from soils treated with 

 different amounts of manure. 



Here, as in the other cases presented, the sulphates recov- 

 ered with distilled water increase with the amounts of manure 

 added, the mean relations standing for the two groups of soils 

 as next given. 



Mean amounts of sulphates, as SO^, recovered from 



