MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 



41 



soils, even with 200 tons of manure per acre, are less in propor- 

 tion to the soil, than were used in the studies of absorption 

 phenomena by the investigators cited in Bulletin D, pages 114 

 to 168. 



AMOUNTS OF SALTS ADDED TO THE SOILS WITH THE MANURE, 



WHICH WERE NOT RECOVERED BY WASHING IN 



DISTILLED WATER. 



If the amounts of water-soluble salts .recovered from the soils 

 to which no manure had been added and those which were 

 added with the manure are considered as the amounts which 

 were present in the several samples at the time they were ex- 

 amined, 65 days after they were manured, the differences be- 

 tween these sums and the amounts which were recovered will 

 represent the quantities which were held back by the soils. 

 In the next table a comparison is made of the averages from 

 the four poorer and from the four stronger soils for each of the 

 different amounts of manure which had been added to them. 



Mean amounts of salts not recovered from (toil 65 days after being 

 treated with stable manure. 



